Search

Objective: To determine the role and mechanism of EphB4 in dasatinib (DAS) resistance in advanced chronic myeloid leukemia (CML), we explored the EphB4-mediated apoptotic and matrix microenvironment pathway in human CML and K562 cell lines., Method: Heparinized bone marrow samples were obtained from enrolled five patients (identified as A to E and visits identified by number) at initial diagnosis (A1-E1) and in the DAS-resistance advanced phase (A2-E2). Meanwhile, highly DAS-resistant cells, named K562-R cells, were obtained from K562-W cells with increasing concentrations of DAS. Stable under-expressing EphB4 cells (K562-R-EphB4-sh) were obtained from K562-R cells by RNA interference. K562-W, K562-R and K562-R-EphB4-sh cells (10 8 ) were respectively injected subcutaneously on the dorsal surface of BALB/C female nude mice to establish the xenografts models., Result: The mRNA/protein of EphB4 was overexpressed in the DAS-resistant A2-E2 in comparison with the A1-E1 human cell lines. Further, compared with K562-R cells, the expressions of EphB4 and p-Rac1/Cdc42 protein/mRNA were significantly downregulated in K562-R-EphB4-sh cells (P<0.01). K562-R cells showed the highest DAS resistance (IC50 10.54±0.67μg/ml), but K562-R-EphB4-sh cells became sensitive to DAS (IC50 1.02±0.1μg/ml, P<0.01). The expression of EphB4/p-RhoA/MCL-1 protein was gradually increased in the stimulating of EphrinB2-Fc, which partly made K562-R-EphB4-sh cells restore sensitivity to DAS (4.18±0.30μg/ml). Meanwhile, the K562-R-EphB4-sh xenografts group had relatively good efficacy compared to K562-R xenografts nude mice receiving the same dose of DAS. The analysis of xenografts tissue also suggested parallel results with the overexpression of EphB4/RhoA/ROCK1/PTEN/MCL-1 in K562-R xenografts, which decreased in the A2-R-EphB4-sh xenografts (P<0.01)., Conclusions: The present study found that a new DAS resistance pathway of EphB4 overexpression was triggered by EphrinB2-Fc, which induced the resistance to DAS by activating RhoA/ROCK1/PTEN/MCL-1 signaling., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Objective: The open-label, prospective, observational study aimed to evaluate whether decitabine (DAC) plus thalidomide versus DAC monotherapy improved progression-free (PFS), overall survival (OS) and acute myeloid leukemia-free survival (AML-FS) for risk-tailored elderly patients with myelodysplastic syndromes (MDS)., Method: Enrolled 107 patients (age: 65-82 years) received DAC (52/107) or DAC plus thalidomide (55/107) therapy for MDS., Results: 35/52 patients (67.3%) with DAC therapy reached overall response (OR), compared with 36/55 patients (65.5%) in DAC+thalidomide regimen (P>0.05). DAC+thalidomide administered did not gain more profits of PFS and OS than DAC monotherapy. Risk-tailored analysis showed that DAC+thalidomide therapy did not enhance PFS (48.9% versus 42.8%, P>0.05) and OS (78.6% versus 71.2%, P>0.05) when compared with simple DAC regimen. Nevertheless, DAC+thalidomide markedly improved OS over DAC monotherapy (50.6% versus 40.2%, P<0.05) in high risk profile. Meanwhile, low risk group was superior to high risk group in AML-FS (57.2% versus 21.3%, P<0.01), but DAC+thalidomide still did not prolong 2-year AML-FS when compared with DAC (32.4% versus 27.8%, P<0.05). Moreover, thalidomide had a favorable toxicity profile as a single agent. In comparison with DAC monotherapy, the DAC+thalidomide regimen was relatively well tolerated. There was no severe non-hematological toxicity appearing in elderly patients with MDS., Conclusions: The study demonstrated that DAC+thalidomide improved 2-year OS for high risk patients. Thalidomide's proven activity and low toxicity profile made it an alternative treatment option for risk-tailored elderly patients with MDS., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Objective: This open-label, prospective, observational study aimed to evaluate treatment response, efficacy therapy and safety to IFN α-2b for the essential thrombocythemia (ET) and polycythemia vera (PV) with JAK2V617F positive mutation., Method: A total of 123 ET patients received IFNα-2b therapy with JAK2V617F positive or negative mutation; and 136 PV patients with JAK2V617F(+) received IFNα-2b or hydroxyurea (HU) therapy according to random number assignment (ages 18-65 years old)., Result: ET patients receiving IFN α-2b with JAK2V617F(+) had a greater advantage in overall hematologic response (OHR) than JAK2V617F(-) (83.3% versus 61.4%, P<0.01). For PV patients with JAK2V617F(+), IFN had no OHR superiority to HU (70.3% versus 70.8%, P>0.05), but which gained a greater satisfactory molecular response than HU (54.7% versus 19.4%, P<0.01). IFN significantly decreased the phlebotomy rate, which was better than HU for MPDs patients with OHR than HU (3.6% versus 65.7%, P<0.01). Furthermore, ET patients with JAK2V617F(+) demonstrated a definite advantage over JAK2V617F(-) in five-year PFS (75.9% versus 47.6%, P<0.05). For PV patients with JAK2V617F(+), IFN α-2b was superior to HU in five-year PFS (66.3% versus 46.7%, P<0.01). Moreover, IFN α-2b also contributed to improved vasomotor symptoms in MPDs, and especially significantly decreased the incidence of distal paresthesias (14.1% versus 37.5%) and erythromelalgia (9.4% versus 29.2%) better than HU (P<0.01). Meanwhile, IFN did not observe the severe hematological adverse events in patients with PV or ET., Conclusion: The data confirmed that IFN α-2b benefited the patients with ET or PV, particularly for JAK2V617F(+) mutation., (Copyright © 2014 Elsevier Ltd. All rights reserved.)