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We sought to determine the expression levels of hypoxia-inducible factor-1α (HIF-1α) in the bone marrow chronic myelogenous leukemia (CML) patients. We also tried to determine the roles HIF-1α in the proliferation of CML cells by small interfering RNA (siRNA) knockdown. Real-time PCR was performed to determine the expression levels of HIF-1α in the bone marrows of CML patients and healthy volunteers. HIF-1α knockdown by siRNA in K562 cells was confirmed by RT-PCR. Proliferation and colony formation of the treated cells were determined by CCK8 after HIF-1α knockdown. RT-PCR and western blotting were performed to detect mRNA and protein levels of p21 and p53 in K562 cells. HIF-1α mRNA expression in the bone marrow of CML patients was significantly higher than that in the control, which was statistically significant (P < 0.05). HIF-1α knockdown dramatically reduced the proliferation of K562 cells, which was also statistically significant (P < 0.05). HIF-1α knockdown markedly reduced the colony formation ability of K562 cells, which was also statistically significant (P < 0.05). The mRNA and protein expression of p21 were significantly reduced in K562 cell after HIF-1α knockdown with affecting the mRNA and protein levels of p53. HIF-α promotes chronic CML cell proliferation by up-regulating p21 expression.

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Objective: JAK2 V617F, MPL W515L and JAK2 exon 12 mutations are novel acquired mutations that induce constitutive cytokine-independent activation of the JAK-STAT pathway in myeloproliferative disorders (MPD). The discovery of these mutations provides novel mechanism for activation of signal transduction in hematopoietic malignancies. This research was to investigate their prevalence in Chinese patients with primary myelofibrosis (PMF).Methods: We introduced allele-specific PCR (AS-PCR) combined with sequence analysis to simultaneously screen JAK2 V617F, MPL W515L and JAK2 exon 12 mutations in 30 patients with PMF.Results: Fifteen PMF patients (50.0%) carried JAK2 V617F mutation, and only two JAK2 V617F-negative patients (6.7%) harbored MPL W515L mutation. None had JAK2 exon 12 mutations. Furthermore, these three mutations were not detected in 50 healthy controls.Conclusion: MPL W515L and JAK2 V617F mutations existed in PMF patients but JAK2 exon 12 mutations not. JAK2 V617F and MPL W515L and mutations might contribute to the primary molecular pathogenesis in patients with PMF.

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Bortezomib has proven to be active in patients with multiple myeloma (MM), including elderly patients. The aim of this study was to evaluate the efficacy and toxicity of bortezomib in combination with intermediate‐dose dexamethasone (Dex) and thalidomide in untreated MM patients aged ≥65 years in a Chinese single center. In this study, 18 patients were treated with bortezomib at 1.3 mg/m2 IV on Days 1, 4, 8, and 11 and Dex at 20 mg/day IV on Days 1–4 and 8–11 simultaneously. Thalidomide at dose of 100 mg/day was given everyday. The mean number of cycles of bortezomib treatment was 2.06. Three patients (17%) achieved a complete response (CR), four (22%) a very good partial response (VGPR), and nine (50%) a PR, resulting in an overall response rate of 89%. The median time to response was 22 days (range 14–50 days). The duration of response was significantly longer in patients achieving a CR/VGPR with respect to those achieving only a PR (8.5 vs. 4.2 months, P = 0.03). Grade 3–4 toxicities occurring in patients comprised weakness, thrombocytopenia, diarrhea, infection, and neuropathy. Only one patient suffered from deep vein thrombosis. This preliminary experience in Chinese patients indicated that bortezomib‐Dex‐thalidomide is highly effective in elderly untreated patients with MM, even in patients with poor prognostic features. Am. J. Hematol. 2010. © 2010 Wiley‐Liss, Inc.

Studies have shown that the bortezomib-based retreatment of patients with multiple myeloma (MM) may prolong control of the disease. The optimal duration of bortezomib-based retreatment in relapsed or refractory MM is unknown. The present retrospective study evaluated the efficacy and safety of short-course bortezomib-based retreatment in patients who had received bortezomib-thalidomide-dexamethasone (VTD) treatment for the initial therapy of newly diagnosed MM. The clinical records of 20 patients who had received short-course bortezomib-based retreatment in a single center were reviewed. Patients received a median of two cycles of bortezomib as the retreatment and the overall response rate was 90%. Six (30%), eight (40%) and four (20%) patients achieved a complete response (CR), a very good partial response and a partial response, respectively. Of the 10 patients who had achieved a CR during the initial VTD treatment, six experienced a repeat CR during the retreatment. The median duration of the response was nine months and the median time to progression was 10.5 months. The most common grade I and II adverse events were thrombocytopenia and neutropenia. The short-course bortezomib-based retreatment was well tolerated and the favorable response rates observed suggest that it may be an effective and convenient treatment option for certain patients, particularly elderly patients.