Clin Cancer Res
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Most patients with chronic-phase chronic myeloid leukemia (CML) who receive imatinib achieve a complete cytogenetic remission (CCgR) and low levels of BCR-ABL transcripts. CCgR is durable in the majority of patients but relapse occurs in a subset. ⋯ In our study, we showed not only that achieving a major molecular remission at 12 months is predictive of a durable cytogenetic remission but also that patients who achieved a major molecular remission (expressed both as the BCR-ABL/beta2 microglobulin ratio % <0.0005 and as a 3-log reduction from median baseline value) already at the time of first achieving a CCgR have significantly longer cytogenetic remission durations than those without this magnitude of molecular response (P < 0.05).
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CpG island methylation status in gastric carcinoma with and without infection of Epstein-Barr virus.
EBV-associated gastric carcinoma shows global CpG island methylation of the promoter region of various cancer-related genes. To further clarify the significance of CpG island methylator phenotype (CIMP) status in gastric carcinoma, we investigated methylation profile and clinicopathologic features including overall survival in four subgroups defined by EBV infection and CIMP status: EBV-associated gastric carcinoma and EBV-negative/CIMP-high (H), EBV-intermediate (I), and EBV-negative (N) gastric carcinoma. ⋯ The methylation profile of five representative genes is useful to stratify gastric carcinomas into biologically different subgroups. EBV-associated gastric carcinoma showed global CpG island methylation, comprising a pathogenetically distinct subgroup in CIMP-H gastric carcinoma.
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On March 25, 2005, bortezomib (Velcade for Injection; Millennium Pharmaceuticals, Inc., Cambridge, MA, and Johnson & Johnson Pharmaceutical Research & Development, L.L.C.) received regular approval from the U.S. Food and Drug Administration (U.S. FDA) for the treatment of multiple myeloma (MM) progressing after at least one prior therapy. This approval was based on bortezomib's efficacy and safety which was shown in a single, large, comparative international open-label phase 3 trial that randomized 669 patients with MM previously treated with at least one systemic regimen to receive single-agent bortezomib or high-dose dexamethasone. The FDA analysis of the trial data and bortezomib's regulatory development are summarized here. ⋯ The U.S. FDA had earlier (May 2003) granted bortezomib accelerated approval for the treatment of patients with MM progressing after two prior therapies. The results of the phase 3 trial and the FDA analysis of the data, along with the sponsor's completion of other postmarketing commitments, confirm bortezomib's benefit and support regular approval.
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Because ribonucleotide reductase (RR) plays a role in DNA repair, it may serve as a molecular target for radiosensitization. Unlike previously investigated RR inhibitors, Triapine potently inhibits both RR holoenzymes. Therefore, the effects of Triapine on tumor cell radiosensitivity were investigated. ⋯ These results indicate that Triapine can enhance tumor cell radiosensitivity in vitro and in vivo and suggest that this effect involves an inhibition of DNA repair.
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The majority of gastrointestinal stromal tumors harbor mutations in the receptor tyrosine kinases KIT or platelet-derived growth factor receptor A (PDGFRA), and respond to treatment with the tyrosine kinase inhibitor imatinib. Some tumors, however, show primary resistance to imatinib treatment, and most others become resistant during treatment. The most common mechanism of imatinib resistance involves specific mutations in the kinase domains of KIT or PDGFRA. We tested the activity of SU11248, an orally active small-molecule tyrosine kinase inhibitor, to inhibit important imatinib-resistant KIT and PDGFRA mutants. ⋯ These studies suggest that SU11248 may be a useful therapeutic agent to treat gastrointestinal stromal tumors harboring the imatinib-resistant KIT-V654A or KIT-T670I mutations, but it has no effect on the activity of the PDGFRA-D842V mutant. Specific kinase inhibitors should be designed to inhibit the constitutive activating PDGFRA mutation at codon 842.