Posted by rob on July 30, 2010 under Uncategorized | 
Seven-year response to imatinib as initial treatment versus re-treatment in Chinese patients with chronic myelogenous leukemia in the chronic phase.
Ann Hematol. 2010 Jul 29;
Authors: Jiang H, Chen SS, Jiang B, Jiang Q, Qin YZ, Lai YY, Huang XJ
The purpose of our study is to compare the 7-year response to imatinib monotherapy as an initial treatment and re-treatment in Chinese patients with chronic myelogenous leukemia-chronic phase (CML-CP) patients in a single center in Beijing. A retrospective study of 171 CML-CP patients receiving imatinib monotherapy was done with 73 in the initial treatment group (disease course </=6 months) and 98 in the re-treatment group (disease course >6 months). Cumulative rates of complete cytogenetic response (CCyR) at 6, 12, and 36 months after imatinib treatment in the initial and re-treatment groups were 75%, 89%, and 96%, and 48%, 77% and 84% (p = 0.0002), respectively. The median time to CCyR in the initial and re-treatment groups was 6 months (95% CI, 3.3-8.3) and 9 months (95% CI, 6.4-11.6), respectively (p = 0.0002). Cumulative rates of major molecular responses at 9, 12, and 18 months after imatinib treatment in the initial and re-treatment groups were 31%, 48%, and 60%, and 15%, 25% and 37% (p = 0.017), respectively. The median time to the major molecular response in the initial and re-treatment groups was 15 months (95% CI, 12.3-17.7) and 36 months (95% CI, 25.9-46.0), respectively (p = 0.017). Progression-free survival at 84 months in the initial and re-treatment groups was 97% and 85%, respectively (p = 0.09). Event-free survival at 84 months in the initial and re-treatment groups was 92% and 70%, respectively (p = 0.049). Only two of the 171 patients discontinued imatinib therapy for grade 3/4 adverse events. Our study revealed that CML-CP patients would benefit from early treatment with imatinib.
PMID: 20668855 [PubMed - as supplied by publisher]
More
Posted by rob on under Uncategorized |
Ocular masquerade syndrome as a herald of progression of acute myelogenous leukemia.
Ann Hematol. 2010 Jul 29;
Authors: Gan NY, King LL, Teoh SC
PMID: 20668854 [PubMed - as supplied by publisher]
More
Posted by rob on under Uncategorized |
PR1-Specific T Cells Are Associated with Unmaintained Cytogenetic Remission of Chronic Myelogenous Leukemia After Interferon Withdrawal.
PLoS One. 2010;5(7):e11770
Authors: Kanodia S, Wieder E, Lu S, Talpaz M, Alatrash G, Clise-Dwyer K, Molldrem JJ
BACKGROUND: Interferon-alpha (IFN) induces complete cytogenetic remission (CCR) in 20-25% CML patients and in a small minority of patients; CCR persists after IFN is stopped. IFN induces CCR in part by increasing cytotoxic T lymphocytes (CTL) specific for PR1, the HLA-A2-restricted 9-mer peptide from proteinase 3 and neutrophil elastase, but it is unknown how CCR persists after IFN is stopped. PRINCIPAL FINDINGS: We reasoned that PR1-CTL persist and mediate CML-specific immunity in patients that maintain CCR after IFN withdrawal. We found that PR1-CTL were increased in peripheral blood of 7/7 HLA-A2+ patients during unmaintained CCR from 3 to 88 months after IFN withdrawal, as compared to no detectable PR1-CTL in 2/2 IFN-treated CML patients not in CCR. Unprimed PR1-CTL secreted IFNgamma and were predominantly CD45RA+/-CD28+CCR7+CD57-, consistent with functional naïve and central memory (CM) T cells. Similarly, following stimulation, proliferation occurred predominantly in CM PR1-CTL, consistent with long-term immunity sustained by self-renewing CM T cells. PR1-CTL were functionally anergic in one patient 6 months prior to cytogenetic relapse at 26 months after IFN withdrawal, and in three relapsed patients PR1-CTL were undetectable but re-emerged 3-6 months after starting imatinib. CONCLUSION: These data support the hypothesis that IFN elicits CML-specific CM CTL that may contribute to continuous CCR after IFN withdrawal and suggest a role for T cell immune therapy with or without tyrosine kinase inhibitors as a strategy to prolong CR in CML.
PMID: 20668669 [PubMed - in process]
More
Posted by rob on under Uncategorized |
Antiproliferative Properties of Type I and Type II Interferon.
Pharmaceuticals (Basel). 2010 Mar 30;3(4):994-1015
Authors: Bekisz J, Baron S, Balinsky C, Morrow A, Zoon KC
The clinical possibilities of interferon (IFN) became apparent with early studies demonstrating that it was capable of inhibiting tumor cells in culture and in vivo using animal models. IFN gained the distinction of being the first recombinant cytokine to be licensed in the USA for the treatment of a malignancy in 1986, with the approval of IFN-alpha2a (Hoffman-La Roche) and IFN-alpha2b (Schering-Plough) for the treatment of Hairy Cell Leukemia. In addition to this application, other approved antitumor applications for IFN-alpha2a are AIDS-related Kaposi’s Sarcoma and Chronic Myelogenous Leukemia (CML) and other approved antitumor applications for IFN-alpha2b are Malignant Melanoma, Follicular Lymphoma, and AIDS-related Kapoisi’s Sarcoma. In the ensuing years, a considerable number of studies have been conducted to establish the mechanisms of the induction and action of IFN’s anti-tumor activity. These include identifying the role of Interferon Regulatory Factor 9 (IRF9) as a key factor in eliciting the antiproliferative effects of IFN-alpha as well as identifying genes induced by IFN that are involved in recognition of tumor cells. Recent studies also show that IFN-activated human monocytes can be used to achieve >95% eradication of select tumor cells. The signaling pathways by which IFN induces apoptosis can vary. IFN treatment induces the tumor suppressor gene p53, which plays a role in apoptosis for some tumors, but it is not essential for the apoptotic response. IFN-alpha also activates phosphatidylinositol 3-kinase (PI3K), which is associated with cell survival. Downstream of PI3K is the mammalian target of rapamycin (mTOR) which, in conjunction with PI3K, may act in signaling induced by growth factors after IFN treatment. This paper will explore the mechanisms by which IFN acts to elicit its antiproliferative effects and more closely examine the clinical applications for the anti-tumor potential of IFN.
PMID: 20664817 [PubMed - as supplied by publisher]
More
Posted by rob on under Uncategorized |
BCR-ABL but not JAK2 V617F inhibits erythropoiesis through the Ras signal by inducing p21CIP1/WAF1.
J Biol Chem. 2010 Jul 27;
Authors: Tokunaga M, Ezoe S, Tanaka H, Satoh Y, Fukushima K, Matsui K, Shibata M, Tanimura A, Oritani K, Matsumura I, Kanakura Y
BCR-ABL is a causative tyrosine kinase (TK) of chronic myelogenous leukemia (CML). In CML patients, although myeloid cells are remarkably proliferating, erythroid cells are rather decreased and anemia is commonly observed. This phenotype is quite different from that observed in polycythemia vera (PV) caused by JAK2 V617F, whereas both oncogenic TKs activate common downstream molecules at the level of hematopoietic stem cells (HSCs). To clarify this mechanism, we investigated the effects of BCR-ABL and JAK2 V617F on erythropoiesis. Enforced expression of BCR-ABL but not of JAK2 V617F in murine LSK (Lineage(-)Sca-1(hi)CD117(hi)) cells inhibited the development of erythroid cells. Among several signaling molecules downstream of BCR-ABL, an active mutant of N-Ras (N-RasE12) but not of STAT5 or phosphatidylinositol 3-kinase (PI3-K) inhibited erythropoiesis, while N-RasE12 enhanced the development of myeloid cells. BCR-ABL activated Ras signal more intensely than JAK2 V617F, and inhibition of Ras by manumycin A, a farnesyltransferase inhibitor, ameliorated erythroid colony formation of CML cells. As for the mechanisms of Ras-induced suppression of erythropoiesis, we found that GATA-1, an erythroid-specific transcription factor, blocked Ras-mediated mitogenic signaling at the level of MEK through the direct interaction. Furthermore, enforced expression of N-RasE12 in LSK cells derived from p53-, p16(INK4a)/p19(ARF)-, and p21(CIP1/WAF1)-null/wild-type mice revealed that suppressed erythroid cell growth by N-RasE12 was restored only by p21(CIP1/WAF1) deficiency, indicating that a cyclin-dependent kinase (CDK) inhibitor, p21(CIP1/WAF1), plays crucial roles in Ras-induced suppression of erythropoiesis. These data would, at least partly, explain why respective oncogenic TKs cause different disease phenotypes.
PMID: 20663870 [PubMed - as supplied by publisher]
More
Posted by rob on under Uncategorized |
Interaction of CJZ3, a lomerizine derivative, with ATPase activity of human P-glycoprotein in doxorubicin-resistant human myelogenous leukemia (K562/DOX) cells.
Pharmazie. 2010 Jul;65(7):515-9
Authors: Ji BS, Li M, He L
P-Glycoprotein, a 170-180 kDa membrane glycoprotein that mediates multidrug resistance, hydrolyses ATP to efflux a broad spectrum of hydrophobic agents. To observe the interaction of a P-gp reversal agent with P-gp ATPase activity should provide further insights into the mechanisms of P-gp modulator. In this study, we analysed the effect of CJZ3, a lomerizine derivative, on the adenosine triphosphatase (ATPase) activity of human P-glycoprotein. The results showed that the basal P-gp ATPase activity was increased by CJZ3 with half-maximal activity concentration (Km) of 6.8 +/- 1.5 microM, CJZ3 may interact with P-gp with a higher affinity and exhibit a more potent effect than verapamil (Ver). Kinetic analysis indicated a noncompetitive inhibition of Ver-stimulated P-gp ATPase activity and a competitive inhibition of CJX2-stimulated P-gp ATPase activity by CJZ3, moreover, the effect of CsA on CJZ3-stimulated and Ver-stimulated P-gp ATPase activity showed a non-competitive and a competitive inhibition respectively. CJZ3 and CJX2 can bind P-gp either on overlapping sites or distinct but interacting sites, while CJZ3 and Ver as well as CsA can bind P-gp on separated sites in K562/DOX cells.
PMID: 20662321 [PubMed - in process]
More
Posted by rob on under Uncategorized |
A unique BCR-ABL1 transcript with the insertion of intronic sequence from BCR and ABL1 genes in a patient with Philadelphia-positive chronic myeloid leukemia: a case study.
Cancer Genet Cytogenet. 2010 Aug;201(1):57-61
Authors: Sadia H, Siddiqui RT, Nasim A
The BCR-ABL1 fusion gene results from a reciprocal translocation rearrangement, t(9;22)(q34;q11.2), and is a hallmark of chronic myeloid leukemia (CML). The breakpoint on chromosome 9 is mostly 5′ to ABL1 exon 2, whereas on chromosome 22, the breakpoint can occur in various regions involving the major breakpoint cluster region (M-bcr) in CML and the minor breakpoint cluster region (m-bcr) in acute lymphoblastic leukemia. Described here is a rare case of Philadelphia-positive CML with intronic splice sites. This atypical BCR-ABL1 transcript was detected along with a classic e13a2 transcript, using reverse transcription polymerase chain reaction (RT-PCR). Nucleotide sequence analysis revealed a joining of BCR intron 13 with ABL1 intron 1a. Both transcripts were detected when the patient was on hydroxyurea treatment; with imatinib mesylate therapy, the atypical transcript disappeared. To our knowledge, this is the first report of BCR-ABL1 transcript with breakpoint occurring within both BCR and ABL1 introns and fusion of intronic sequences from both BCR and ABL1 genes.
PMID: 20633771 [PubMed - indexed for MEDLINE]
More
Posted by rob on under Uncategorized |
Imatinib (Gleevec) as a paradigm of targeted cancer therapies.
Keio J Med. 2010 Mar;59(1):1-3
Authors: Druker B
PMID: 20375651 [PubMed - indexed for MEDLINE]
More
Posted by rob on under Uncategorized |
New opportunities to treat the T315I-Bcr-Abl mutant in chronic myeloid leukaemia: tyrosine kinase inhibitors and molecules that act by alternative mechanisms.
Curr Med Chem. 2010;17(13):1220-45
Authors: Schenone S, Brullo C, Botta M
Resistance to the Bcr-Abl inhibitors approved for the treatment of chronic myeloid leukaemia (CML) may arise from different mechanisms, including Bcr-Abl amino acid mutations, gene amplification and mechanisms independent of Bcr-Abl. The T315I mutation at the gatekeeper residue is very frequent in advanced phases of the disease and is one of the main causes of resistance, disrupting important contact points between the inhibitors and the enzyme. Different strategies have been implemented to overcome this resistance, including the synthesis of new Bcr-Abl ATPcompetitive or non-ATP-competitive inhibitors, dual Aurora/Bcr-Abl inhibitors and multi-targeted kinase inhibitors. An alternative approach is the use of other compounds that do not bind directly to the Bcr-Abl protein; instead, these molecules act on several downstream pathways, regulated by or linked in different ways to Bcr-Abl, that lead to the malignant transformation of the cells. For this reason, farnesyl transferase inhibitors, MAPK inhibitors, Rac guanosine triphosphatase inhibitors, PI3K inhibitors, JAK inhibitors, Hsp90 inhibitors, mTOR inhibitors, PP2A activators and apoptosis inducers have been tested, alone or in combination with ATP-competitive inhibitors, against CML cell lines. This review discusses compounds that act on Bcr-Abl or different cell pathways and reports on the molecules active against the T315I mutation, particularly the most recent findings in this field. New molecules that are claimed by recent patents to be active on this mutation are also reported. When possible, the review will focus on medicinal chemistry in terms of chemical structure, mechanism of action and structure-activity relationships.
PMID: 20166937 [PubMed - indexed for MEDLINE]
More
Posted by rob on under Uncategorized |
Abstract The purpose of our study is to compare the 7-year response to imatinib monotherapy as an initial treatment and re-treatment
in Chinese patients with chronic myelogenous leukemia-chronic phase (CML-CP) patients in a single center in Beijing. A retrospective
study of 171 CML-CP patients receiving imatinib monotherapy was done with 73 in the initial treatment group (disease course
?6 months) and 98 in the re-treatment group (disease course >6 months). Cumulative rates of complete cytogenetic response
(CCyR) at 6, 12, and 36 months after imatinib treatment in the initial and re-treatment groups were 75%, 89%, and 96%, and
48%, 77% and 84% (p?=?0.0002), respectively. The median time to CCyR in the initial and re-treatment groups was 6 months…
More
