Leukemias induced by ethylnitrosourea in Wistar rats: incidence and chemotherapy.

After application of 15 mg/kg ethylnitrosourea (ENU) weekly for 15 weeks to 200 male Wistar rats, 76 developed acute leukemias, 15 developed chronic myeloid leukemias and 39 had malignomas in other organs. The weekly application of 75 mg/kg ENU to another group of 200 male Wistar rats for 3 weeks caused 57 acute leukemias, 6 chronic myeloid leukemias and 47 malignomas in other organs. From 112 “autochthonous” acute leukemias which were treated with a combination of vincristine, adriamycin and cytosine arabinoside (ADOA), 67 (60%) achieved a complete remission with a median survival time of 64 days (range 25–173). The survival time of this group was significantly increased compared to untreated controls (α = 0.01). Forty-five rats (40%) with acute leukemia died during the first week after start of therapy, or therapy had to be discontinued. The failure of treatment in this group was attributed to the poor general condition of the animals whose platelet counts and hemoglobin values were low, due to late diagnosis.The “autochthonous” acute leukemias demonstrated some parallels with human acute leukemia. Their use in experimental chemotherapy is discussed.     

刺五加对阿糖胞苷损伤的骨髓间充质干细胞的保护作用

目的探讨刺五加注射液对阿糖胞苷损伤的骨髓间充质干细胞(BMSCs)的保护作用。方法体外密度梯度法分离培养大鼠骨髓间质干细胞,设置对照组与不同浓度的阿糖胞苷组、刺五加注射液组和阿糖胞苷、刺五加注射液联合组。采用四甲基偶氮唑蓝(NTT)法检测各组细胞存活和生长情况。结果①5种浓度的阿糖胞苷对MSC的抑制作用与对照组比较有显著性差异(P<0.05),细胞抑制率随着浓度的增高而增高。②5种浓度的刺五加注射液对MSC的增值作用与对照组比较有显著性差异(P<0.05)。③联合组与单独用药组对MSC的增值作用比较有显著性差异(P<0.05)。结论刺五加注射液对阿糖胞苷损伤的骨髓间充质干细胞有一定的保护作用。     

Survivin shRNA促进HL-60细胞凋亡及其对阿糖胞苷敏感性的研究

目的研究RNA干扰Survivin基因表达对HL-60细胞凋亡及其对阿糖胞苷敏感性的影响。方法采用PCR扩增以及定向克隆技术重组构建shRNA的表达载体pshRNA-Survivin,使用脂质体介导转染至HL-60细胞,分为6组：①空白实验组;②阿糖胞苷（Ara-C）组;③阳性质粒组;④阴性质粒组;⑤阳性质粒＋Ara-C组;⑥阴性质粒＋Ara-C组。采用RT-PCR技术检测HL-60细胞内Survivin及其mRNA表达,运用流式细胞仪进行细胞凋亡率改变的检测。结果与空白实验组比较,阳性质粒组的mRNA表达抑制率为57.7%,表达下降,差异有统计学意义（P〈0.05）;阳性质粒组细胞凋亡率为5.87%,阳性质粒＋Ara-C组细胞对Ara-C敏感性明显提高,细胞凋亡率为12.4%,差异有统计学意义（P〈0.05）。结论 Survivin siRNA能够高效特异的抑制HL-60细胞内Survivin基因的表达,诱导细胞凋亡,并提高了HL-60细胞对Ara-C的敏感性,这有助于白血病基因治疗的进一步发展。     

STI571/doxorubicin concentration-dependent switch for diverse caspase actions in CML cell line K562

We examined the response of the apoptosis-reluctant CML cell line K562 to doxorubicin alone or in combination with the tyrosine kinase inhibitor STI571. We found that at clinically relevant concentrations, doxorubicin induced differentiation and senescence, but did not induce apoptosis. Doxorubicin induced G(2)/M arrest and mitochondrial transmembrane potential dissipation. Interestingly, drug-induced differentiation could be diminished by caspase inhibitors. STI571 caused a graded response characterized by differentiation at low concentrations and apoptosis at higher. STI571 was not observed to induce senescence. Combination of STI571 and caspase inhibitors protected cells from apoptosis but did not influence differentiation. The diverse mode of action of both drugs contributed to the response observed during combination treatment. An additive effect on proliferation was obtained. The mechanisms contributing to inhibition of cellular proliferation were complex and strongly dependent on the applied drug concentrations. Differentiation or apoptosis were enhanced by combined treatment only in narrow ranges of concentrations. Conclusion: DOX and STI571 along diverse mechanisms contributed to elevated levels of activated caspases which might be then responsible for a switch from differentiation to apoptosis.     

胞苷脱氨酶基因对小鼠大剂量化疗的保护作用

Objective:To explore the feasibility of transfecting cytidine deaminase(CD)gene into mouse bone marrow cells in order to observe the drug resistance of high dose Ara-C and improve the tolerance of myelosuppression following combination chemotherapy.Methods:Human cytidine deaminase gene was transfected into mice bone marrow cells by retroviral vector.Resistant colony-forming unit granulocyte-macrophage(CFU-GM)assay was performed after the transfected mice bone marrow cells treated by the Ara-C.DNA was extracted from mice bone marrow cells.The drug resistant gene in mice bone marrow cells after transfection was detected by PCR.Results:Bone marrow cells of lhe donor mice cultured with lhe retroviral producer cells showed the drug resistant colonies and resistance to Ara-C,so did accept mice transplanted with the CD gene(CFU-GM of donor mice was 52%,X2=124.62,P＜0.01:accept mice was 54%,X2=126.26.P＜0.01,both compared with the contrast group).The animal survival rate was significantly higher in gene transfected group than that of the control(X2=7.42.P＜0.01).CD gene of transfected bone marrow cells was confirmed by PCR.Conclusion:CD gene can be transfected into bone marrow cells of mice efficiently and increase the drug resistance to Ara-C.     

美罗华联合Hyper-CVAD/MTX+Ara-C方案治疗高危青年伯基特淋巴瘤的疗效观察（附6例）

目的:分析美罗华联合Hyper-CVAD/MTX+Ara-C方案治疗高危青年伯基特淋巴瘤的治疗效果。方法:总结2014年10月至2016年10月,我院收治的6例伯基特淋巴瘤患者的特征，均采用美罗华联合Hyper-CVAD/MTX+Ara-C方案化疗，历时4个周期共8个疗程，病程中腰穿及鞘注。结果:6例初诊患者临床分期(Arbor分期)Ⅲ期1例，Ⅳ期5例；首发部位多见于腹部包块及浅表淋巴结，均有B症状，乳酸脱氢酶（LDH）水平偏高，骨髓侵犯3例，中枢神经系统侵犯1例，有结外侵犯者3例。总疗程结束后评估，CR 5例，PR 1例，平均缓解期2.3个月。随访2.5年，5例患者病情稳定，1例死亡。结论:美罗华联合Hyper-CVAD/MTX+Ara-C方案治疗高危青年伯基特淋巴瘤有一定效果，患者对联合化疗的耐受性尚可。     

大剂量阿糖胞苷的临床药代动力学研究及毒副反应观察

应用反相高压液相色谱（ＨＰＬＣ）技术，研究８例急性髓细胞白血病（ＡＭＬ）缓解后使用大剂量阿糖胞苷（ＨＤＡｒａ－Ｃ）的临床药代动力学，发现用ＨＤＡｒａ－Ｃ３．０ｇ／次静滴２小时，药物在血浆中达到高峰浓度时间为９０分钟，峰浓度平均为５．５９μｇ／ｍｌ，滴注结束后迅速下降，４小时后降至０．１４μｇ／ｍｌ，ＡｒａＣ在体内以及双相清除，ｔ１／２α，ｔ１／２β平均分别为９．６分钟和１９２分钟，体内平均清除率４     

In vitro response of blasts to IL-3, GM-CSF,and G-CSF is different for individual AML patients: factors that stimulate leukemic clonogenic cells also enhance Ara-C cytotoxicity

Summary In vivo, growth factors are currently investigated for their capacity to trigger leukemic stem cells into cycle and thus overcome kinetic drug resistance. In this study, the susceptibility of leukemic clonogenic cells to individual growth factors was related to cytosine-arabinoside (Ara-C) sensitivity. The effects of interleukin-3 (IL-3), granulocyte-macrophage colonystimulating factor (GM-CSF), granulocyte colony-stimulating factor (G-CSF), and combinations of these recombinant hematopoietic factors were tested on blast cells of nine acute myeloid leukemia (AML) patients. Growth factor responses were assessed in semi-solid clonogenic assay and in a 10-day liquid culture followed by clonogenic assay. Heterogeneity in growth factor response was observed in both test systems, resulting in a variable pattern for individual leukemias. In the majority of cases (six of nine) the response patterns in the semi-solid and liquid cultures were divergent. To test the Ara-C sensitivity, leukemic blasts were exposed in liquid to various concentrations of Ara-C in the absence and presence of preselected growth factors. After 10 days, the number of surviving leukemic colony-forming cells (CFU-L) was assessed. Exposure to Ara-C in the presence of optimal stimulatory factor(s) resulted in a 3- to 1000-fold increase of the Ara-C toxicity in seven patients. The Ara-C concentrations resulting in 50% inhibition of clonogenicity (ID₅₀) were 0.48–123 x 10^–8 M Ara-C in the absence of stimulatory growth factors, versus only 0.12–0.40 × 10^–8 M Ara-C in the presence of these factors. In two patients, addition of one or more factors neither increased the number of CFU-L in liquid nor enhanced the Ara-C toxicity. Even in the absence of growth factors the ID₅₀ values in these cases were as low as 0.20 and 0.28 × 10^–8 M Ara-C and in the same range as the ID₅₀ values observed with maximum growth factor stimulation in the other seven patients. These results indicate that Ara-C cytotoxicity can be enhanced by individually selected, clonogenic cell growth-promoting hematopoietic factors.     

High-dose cytarabine in upfront therapy for adult patients with acute lymphoblastic leukaemia

Summary. In this national study, we have evaluated a new intensive chemotherapy protocol for adult patients with untreated acute lymphoblastic leukaemia (ALL). One hundred and fifty-three patients with median age 42 years received induction therapy with high-dose cytarabine (Ara-C), cyclophosphamide, daunorubicin, vincristine and betamethasone. A high complete remission (CR) rate (90%) was achieved in patients < 60 years compared with 70% in patients > 60 years ( P  = 0·004). The estimated 3 year overall survival for all patients was 29% (CI 21–36%) and the estimated continuous complete remission (CCR) at 3 years for the patients achieving CR according to the protocol was 36% (CI 27–45%). A favourable pretreatment characteristic was pre-B phenotype, especially for patients < 40 years without any high-risk factor, with an estimated CCR at 3 years of 62% (CI 41–82%). Stem cell transplantation (SCT) as post-remission therapy, mainly for high-risk patients, gave an estimated 3 year disease free survival (DFS) after SCT of 39% (CI 24–54%). No significant differences in DFS could be found between autologous, related or unrelated donor transplantation. We conclude that this intensive protocol resulted in a high CR rate combined with acceptable side-effects and a favourable CCR for patients with pre-B ALL.     

Adding low-dose gemtuzumab ozogamicin to fludarabine, Ara-C and idarubicin (MY-FLAI) may improve disease-free and overall survival in elderly patients with non-M3 acute myeloid leukaemia: results of a prospective, pilot, multi-centre trial and comparison with a historical cohort of patients

We report the final results of a prospective multi-centre trial testing the combination of chemotherapy (fludarabine, cytosine arabinoside and idarubicin; FLAI) followed by low-dose gemtuzumab ozogamicin (GO), for induction treatment of patients with CD33+ acute myeloid leukaemia (AML). Forty-six consecutive patients were treated: the median age was 66 (range: 60-80) years; the karyotype was unfavourable in 12 patients (26%), intermediate in 33 (71%) and favourable in one (3%). Eleven major infectious complications were recorded. There was one early death. Of the 45 evaluable patients, 24 achieved a complete response (CR; 52%), 66% and 33% in good-intermediate/poor karyotype patients. Median duration of CR was 7 (3-24) months. The cumulative incidence of relapse was 37% with an actuarial 2-year survival of 54%. These results were compared with 47 patients matched for age and karyotype who received FLAI, without GO. The proportion of patients achieving CR was comparable. However, patients with de novo AML receiving GO (n = 26) had a significantly lower risk of relapse at 2 years when compared with patients not receiving GO (n = 35) (40% vs. 80%, P = 0.01) and significantly better overall 2-year survival (40% vs. 14%P = 0.02). Patients with secondary AML had comparable outcome whether or not they received GO. This GO-based induction chemotherapy has a good toxicity profile. In keeping with a recent prospective randomised trial, the addition of GO seems to prolong disease-free survival.