Priming with G-CSF effectively enhances low-dose Ara-C-induced in vivo apoptosis in myeloid leukemia cells

Venetoclax with CAG regimen for early T-cell precursor acute lymphoblastic leukemia: a case report and literature review

This article describes a potential treatment for early T-cell precursor acute lymphoblastic leukemia (ETP-ALL), a relatively rare and highly aggressive hematologic malignancy. A 59-year-old woman admitted to our hospital with enlarged cervical lymph nodes, weight loss, abnormal count, and morphology of peripheral blood cells was diagnosed with ETP-ALL according to morphology, immunology, cytogenetics, and molecular biology. The patient initially received two cycles of the VICP regimen, including vincristine, idarubicin, cyclophosphamide, and prednisone, and had a response with positive minimal residual disease (MRD). The patient was then given venetoclax plus the CAG regimen, including aclarubicin, cytosine arabinoside, and granulocyte colony-stimulating factor. After one cycle, the patient achieved complete remission with negative MRD and was eligible for allogeneic hematopoietic stem cell transplantation.

Priming with GM-CSF instead of G-CSF enhances CAG-induced apoptosis of acute monocytic leukemia cells in vitro

High expression of granulocyte-macrophage colony-stimulating factor (GM-CSF) receptor has been found in myelomonocytic or monocytic subtypes (M4/M5) of acute myeloid leukemia. Herein, we aimed to improve the effect of CAG [Ara-C, ACR, and G-CSF (granulocyte colony-stimulating factor)] regimen for acute monocytic leukemia by replacing G-CSF with GM-CSF. Results showed that the percentage of cells in S phase was higher with GM-CSF than with G-CSF treatment at 20 ng/mL (P < 0.05). When THP-1 and SHI-1 cells were primed with 20 ng/mL G-CSF or GM-CSF followed by Ara-C and ACR, cell proliferation rate in the CAGM (Ara-C, ACR, and GM-CSF) regimen was lower than in the CAG regimen (P < 0.05). Furthermore, CAGM regimen induced more obvious cell apoptosis than CAG regimen probably by reducing Bcl-2/Bax ratio (P < 0.05). Similar results were seen in primary cells from M5 patients. Collectively, our study suggests that priming with GM-CSF may be more effective than G-CSF in CAG regimen in acute monocytic leukemia.

Efficacy of high-dose cytarabine and aclarubicin in combination with G-CSF regimen compared to intermediate/high-dose cytarabine and standard-dose cytarabine induction regimen for non-remission acute myeloid leukemia

BACKGROUND

Acute myeloid leukemia (AML) patients with non-remission (NR) after the first cycle of standard induction chemotherapy remain a challenge owing to poor response and tolerance to re-induction regimen. We retrospectively evaluated the efficacy and safety of three regimens in AML patients refractory to the first course of standard induction regimen.

MATERIALS AND METHODS

The three regimens consisted of (1) High-dose cytarabine, aclarubicin and granulocyte colony-stimulating factor (HD-CAG) regimen (n = 44); (2) intermediate/high-dose cytarabine (I/HDAC) regimen (n = 30); and (3) standard-dose cytarabine (SDAC) combination regimen that was identical to the first course of standard induction regimen (n = 27).

RESULTS

Results indicated that after the second course, the overall response (OR), i.e., complete remission [CR]+partial remission [PR]) rates in HD-CAG was higher than in the I/HDAC group (84.1% vs. 56.7%, P = 0.009), whereas the CR rates among 3 groups were not statistically different (P = 0.541). Meanwhile, the proportion of subjects reporting certain adverse effects in the HD-CAG group was lower than the I/HDAC or SDAC groups. There were no significant differences in overall survival (OS) and disease-free survival (DFS) rates among the 3 groups (P = 0.881 and P = 0.872, respectively).

CONCLUSION

Our preliminary results indicate that HD-CAG regimen may represent a better alternative option for AML patients with NR after the first course of standard induction chemotherapy.

HAG (Homoharringtonine, Cytarabine, G-CSF) Regimen for the Treatment of Acute Myeloid Leukemia and Myelodysplastic Syndrome: A Meta-Analysis with 2,314 Participants

BACKGROUND

In China, the combination of homoharringtonine, cytarabine, and G-CSF (HAG) has been extensively applied for treatment of acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS).

METHODS

We performed a meta-analysis of 2,314 patients (AML, n = 1754; MDS, n = 560) to determine the overall safety and efficacy of this regimen.

RESULTS

The complete response (CR) rate of AML patients (53%) was significantly higher than that of MDS/transformed-AML patients (45%; P = 0.007). The CR rate of patients with newly diagnosed AML (62%) was significantly higher than in patients with relapsed/refractory AML (50%; P = 0.001). There were no significant difference in CR rates between elderly AML patients (54%) and all AML patients (P = 0.721). When compared with non-HAG regimens for AML/MDS induction therapy, the CR rate of patients treated with HAG was significantly higher than in treated with intensive chemotherapy (P = 0.000). No significant differences in CR rates were observed between patients treated with HAG and those treated with CAG (cytarabine, aclarubicin, G-CSF) regimens (P = 0.073). HAG regimen was well tolerated, with early death (ED) in 2%, grade IV myelosurrpression in 52% and infection in 50%. Reports of ED and rates of myelosuppression were reduced as compared with intensive chemotherapy (P = 0.000 and P = 0.000, respectively).

CONCLUSION

The HAG regimen is an effective and safe regimen for the treatment of AML and MDS, and appears to be more effective and better tolerated than intensive chemotherapy. Future randomized controlled trials and further meta-analyses are strongly needed to confirm its efficacy and safety, especially in comparison with intensive chemotherapy.

Granulocyte colony-stimulating factor inhibits CXCR4/SDF-1α signaling and overcomes stromal-mediated drug resistance in the HL-60 cell line

Combining cytarabine, aclarubicin and granulocyte colony-stimulating factor (G-CSF) has demonstrated marked efficacy in the treatment of elderly and relapsed/refractory patients with acute myeloid leukemia (AML); however, the role of G-CSF remains poorly understood. The present study aimed to investigate the ability of G-CSF to overcome stromal-mediated drug resistance and the underlying molecular mechanism. Two types of co-culture models were established in the HS-5 human bone marrow/stromal and HL-60 human promyelocytic leukemia cell lines, in order to imitate the interactions between stromal and leukemia cells in vitro, which is mediated by the stromal cell-derived factor (SDF)-1α signaling axis. In the present study, HL-60 cells were attracted and adhered to HS-5 cells using migration assay and flow cytometry, respectively; however, these interactions were inhibited by treatment with G-CSF and/or the C-X-C chemokine receptor type 4 (CXCR4) antagonist, AMD3100. Co-culture with HS-5 cells, including direct and indirect contact, protected HL-60 cells against spontaneous apoptosis or drug-induced apoptosis; however, these protective effects were disrupted by treatment with G-CSF and/or AMD3100. Notably, G-CSF and/or AMD3100 did not alter cell viability or apoptosis when HL-60 cells were cultured with medium alone. In addition, G-CSF significantly reduced the expression levels of surface CXCR4 protein, total CXCR4 protein and CXCR4 mRNA, and significantly upregulated the expression of microRNA (miR)-146a. Conversely, AMD3100 significantly reduced surface CXCR4 expression levels, but not the total CXCR4, CXCR4 mRNA or miR-146a expression levels. The results of the present study suggested that interfering with the CXCR4/SDF-1α signaling axis via G-CSF inhibited the migration and adhesion of HL-60 cells to HS-5 cells and eliminated HS5 cell-mediated protective effects. Furthermore, G-CSF administration reduced CXCR4 expression levels by upregulating the expression of miR-146a, whereas AMD3100 appeared to be predominantly dependent on receptor internalization. Therefore, a G-CSF/miR-146a/CXCR4 pathway may explain how G-CSF inhibits CXCR4/SDF-1α signaling and overcomes stromal cell-mediated drug resistance in acute myeloid leukemia.

Efficacy of cytarabine, aclarubicin and granulocyte colony-stimulating factor (CAG) regimen compared to FLAG regimen for adult patients with relapsed/refractory Philadelphia chromosome-negative acute lymphoblastic leukemia

In this study, we retrospectively assess the results in comparing the efficacies and toxicities of the three chemotherapy regimens: CAG (cytarabine, aclarubicin and granulocyte colony-stimulating factor (G-CSF), n=87), HD-CAG (increasing the dose of aclarubicin in CAG regimen, n=73), and FLAG (fludarabine, cytarabine and G-CSF, n=41) regimens in patients with relapsed/refractory Philadelphia chromosome-negative acute lymphoblastic leukemia (Ph--ALL). Our study indicated that after one therapy course, the overall response (OR, complete reimssion (CR)+partial remission (PR)) rate was higher in CAG than that in FLAG regimen (55.2% vs. 31.7%, P=0.013), while the CR (50.7% vs. 26.8%, P =0.013) and OR (64.4% vs. 31.7%, P=0.001) rates in HD-CAG regimen were both higher than that in FLAG regimen. Furthermore, the results were more pronounced in the subgroup of patients with T cell and refractory Ph--ALL. There were no significant differences in CR and OR rates between the CAG and HD-CAG regimens. Meanwhile, the adverse effects of CAG regimen were less toxic than the FLAG and HD-CAG regimens. There were no statistically significant differences in overall survival rates at two years among the three groups (FLAG: 9.8%±4.6%, CAG: 11.8%±4.5%, HD-CAG: 11.1%±4.0%; P>0.05). Our preliminary results indicated that CAG and HD-CAG regimens could be more effective and safer than FLAG regimen for relapsed/refractory Ph--ALL.

Efficacy of low-dose cytarabine and aclarubicin in combination with granulocyte colony-stimulating factor (CAG regimen) compared to Hyper-CVAD regimen as salvage chemotherapy in relapsed/refractory Philadelphia chromosome-negative acute lymphoblastic leukemia

We treated 90 relapsed/refractory Philadelphia chromosome-negative acute lymphoblastic leukemia (Ph(-)-ALL) patients with CAG regimen [cytarabine (10mg/m(2)/12h, days 1-14), aclarubicin (5-7 mg/m(2)/day, days 1-8), granulocyte colony-stimulating factor (200 μg/m(2)/day, days 1-14)], 82 relapsed/refractory Ph(-)-ALL patients were treated with increasing aclarubicin dose CAG (5-7 mg/m(2)/day, days 1-14, HD-CAG). 96 relapsed/refractory Ph(-)-ALL patients treated with Hyper-CVAD regimen (control group). After one therapy course, among all groups, there were no statistically significant differences with complete remission (CR) and overall response [OR, CR+partial remission (PR)] rates (P>0.05). In CAG group, CR and OR rates for T-ALL exceeded those for B-ALL (P=0.001, 0.007), while in HD-CAG and control groups, those were not statistically significantly different (P>0.05). CR and OR rates of CAG group for B-ALL were lower than control group (P=0.004, 0.012). Among all groups, there were no statistically significant differences with CR and OR rates for T-ALL (P>0.05). CAG had lesser adverse event than Hyper-CVAD. The overall survival at 3 years for all groups were similar. Efficacy of CAG regimen was similar in comparison to Hyper-CVAD for relapsed/refractory Ph(-)-T-ALL. HD-CAG could not improve efficacy than CAG regimen.

Low-dose homoharringtonine and cytarabine in combination with granulocyte colony-stimulating factor for elderly patients with de novo acute myeloid leukemia

The treatment of young patient with acute myeloid leukemia (AML) has improved dramatically during the past several decades. However, management of elderly patients with AML still remains a challenge. A total of 56 elderly patients with de novo AML were treated with homoharringtonine and cytarabine in combination with granulocyte colony-stimulating factor (HCG). The overall response rate was 75% (60.7%% complete response [CR] and 14.3% partial response). Fourteen (25%) of the 56 patients showed no response. A higher CR rate was observed in patients aged < 70 years, with better-risk or intermediate-risk karyotype and with NPM1 mutations. To the date of the last follow-up, the median overall survival (OS) was 12.0±1.7 months. There were significant correlations of OS with age, initial karyotype, performance status and gene mutations (NPM1,FLT-ITD and DNMT3A) at diagnosis. The early death rate was 7.1%. Hematologic toxicity was well tolerated; and severe non-hematologic toxicity was not observed.

Increasing the dose of aclarubicin in low-dose cytarabine and aclarubicin in combination with granulocyte colony-stimulating factor (CAG regimen) can safely and effectively treat relapsed or refractory acute myeloid leukemia

It is difficult for relapsed and refractory acute myeloid leukemia (AML) patients to achieve complete remission (CR). The CAG regimen [low-dose cytarabine and aclarubicin in combination with granulocyte colony-stimulating factor (G-CSF)] has been used to treat relapsed and refractory AML patients, and showed good therapeutic efficacy. It is unknown, however, whether increasing the dose of aclarubicin in CAG regimen could treat relapsed or refractory AML safely and effectively. We evaluate the efficacy and tolerability of increasing the dose of aclarubicin in CAG regimen, in 37 relapsed or refractory AML patients. All patients were treated with CAG regimen including low-dose cytarabine (10 mg/m(2) every 12 h, days 1-14), aclarubicin (5-7 mg/m(2) every day, days 1-14), and G-CSF (200 μg/m(2) every day, days 1-14) priming. After a single course of therapy, the overall response [CR + partial remission (PR)] rate of all patients was 78.4 % (29/37), in which the CR rate was 62.2 % (23/37). There was no early death. The median overall survival was 6 months (range 2-36 months). Myelosuppression was ubiquitous, but tolerated. No severe non-hematologic toxicity was observed. Thus, increasing the dose of aclarubicin in CAG regimen can be used safely and effectively in the treatment of relapsed or refractory AML.

Mutations of the epigenetics-modifying gene (DNMT3a, TET2, IDH1/2) at diagnosis may induce FLT3-ITD at relapse in de novo acute myeloid leukemia

Gene mutations were found in acute myeloid leukemia (AML) and their importance has been noted. To clarify the importance and stability of mutations, we examined gene mutations in paired samples at diagnosis and relapse of 34 adult AML patients. Five acquired gene mutations were detected at relapse. Of the 45 gene mutations at diagnosis, 11 of them were lost at relapse. The acquired mutations at relapse were all class I mutations as Fms-like tyrosine kinase 3 (FLT3) and rat sarcoma viral oncogene homolog (RAS) mutations. The disappeared mutations at relapse were 3 of 11 internal tandem duplications of FLT3 (FLT3-ITD) (27.3%), 3 of 3 FLT3 tyrosine kinase domain (FLT3-TKD) (100%), 3 of 13 Nucleophosmin 1 (23.1%) and 2 of 5 CCAAT/enhancer-binding protein-α (40%) mutations. However, epigenetics-modifying gene (DNMT3a, TET2 and IDH1/2) mutations had no change between diagnosis and relapse samples, and may become minimal residual disease marker. The frequency of FLT3-ITD at relapse in patients with DNMT3a mutation at diagnosis is significantly higher than those in patients without them (P=0.001). Moreover, the high frequency of FLT3-ITD at relapse is also seen in AML cases that initially present with any epigenetics-modifying gene mutations (P<0.001). Our results indicate that epigenetics-modifying gene mutations may cause genetic instability and induce FLT3-ITD, leading to resistance to therapy and relapse.

Advances in haematological pharmacotherapy in 21st century

Last quarter of twentieth century and the first 10 years of 21st century has seen phenomenal development in haematological pharmacotherapy. Tailor made chemotherapeutic agents, vast array of monoclonal antibodies, epigenetic modifiers, growth factors for red cells white cells and platelets, peptidomimetics as growth factors, newer thrombin inhibitors, safer plasma derived protein molecules, recombinant molecules, newer immunomodulators, enzyme replacement therapy and above all a plethora of targetted molecules targeting innumerable pathways involved in cell division, growth, proliferation and apoptosis has given immense number of clinically usable molecules in the hand of modern haematologists to treat diverse hitherto untreatable haematological disorders effectively. In addition many old molecules are finding newer uses in diverse fields, thalidomide as an antiangiogenic molecule is a prime example of this genre. Present overview has tried to capture this rapidly evolving area in a broad canvas without going into details of indications and contraindications of the use of various drugs.

Effect of low-dose cytarabine, homoharringtonine and granulocyte colony-stimulating factor priming regimen on patients with advanced myelodysplastic syndrome or acute myeloid leukemia transformed from myelodysplastic syndrome

A total of 32 patients (25 with advanced MDS and 7 with t-AML) were enrolled in this study to evaluate the efficacy and toxicity of the low-dose cytarabine and homoharringtonine in combination with granulocyte colony-stimulating factor (G-CSF) (CHG protocol) in patients with advanced myelodysplastic syndromes (MDS) or MDS-transformed acute myeloid leukemia (t-AML). All the patients were administered the CHG regimen comprising low-dose cytarabine (25 mg/day, intravenous continuous infusion, days 1-14), homoharringtonine (1 mg/day, intravenous continuous infusion, days 1-14), and G-CSF (300 microg/day, subcutaneous injection, days 0-14, interrupted when the peripheral white blood cell count reached >20 x 10(9)/L). The overall response rate was 71.9% after the administration of one course of the CHG regimen. Of the 32 patients, 15 (46.9%) achieved complete remission (CR) and 8 (25%) achieved partial remission (PR). This regimen was followed by a post-remission therapy that included conventional chemotherapy, when CR was achieved. Of the patients with CR who just received post-remission regimens as homoharringtonine and cytarabine (HA) and daunorubicin and cytarabine (DA) 6 relapsed rapidly and just had a mean 6.1 months of CR. Otherwise, the other 8 out of 14 patients with CR alternatively received subsequent chemotherapy, which combined mitoxantrone, idarubicin, pirarubicin, or aclarubicin with cytarabine. The mean CR duration of the 8 patients had reached 10.6 months, and 5 of the 8 still kept a continuous CR. The median overall survival (OS) was 18.2 months. There were no statistically significant differences for CR, PR, and OS when the patients were grouped by age, blasts in bone marrow, and karyotypes, respectively. No treatment-related deaths were observed. Myelosuppression was mild to moderate, and no severe non-hematological toxicity was observed. Thus, a CHG priming regimen as an induction therapy was well tolerated and effective in patients with advanced MDS or t-AML. Stronger and alternative subsequent chemotherapy is necessary for patients with CR to maintain longer CR and better OS.

Low dose of homoharringtonine and cytarabine combined with granulocyte colony-stimulating factor priming on the outcome of relapsed or refractory acute myeloid leukemia

BACKGROUND

To explore the effect of low dose of homoharringtonine (HHT) and cytarabine (Ara-c) combined with granulocyte colony-stimulating factor (G-CSF) priming (HAG regimen) on relapsed or refractory acute myeloid leukemia (AML).

METHODS

Sixty-seven patients with relapsed or refractory acute myeloid leukemia (AML) were enrolled. All the patients were treated with HAG regimen (HHT 1.5 mg/m(2)/day, 1-14d; Ara-C 7.5 mg/m(2)/12 h, 1-14d; G-CSF 150 μg/m(2)/day, according to the counting of the peripheral white blood cells). Blood cell counting, liver, kidney function, ECG and myocardial enzymes were monitored regularly.

RESULTS

Thirty-five of 67 (52.2%) patients achieved complete remission (CR) and 8/67 (11.9%) partial remission (PR). The overall response rate was 64.1%. Myelosuppression was the most frequently observed adverse effect. Sixty of 67 (89.5%) patients suffered from grade 1-4 adverse effects of hematologic toxicity (according to World Health Organization criteria) and non-hematologic toxicity was mild.

CONCLUSION

In conclusion, HAG regimen was effective and tolerated well in refractory or relapsed AML. As a promising regimen for relapse or refractory AML, further observations should be made.

Salvage chemotherapy with low-dose cytarabine and aclarubicin in combination with granulocyte colony-stimulating factor priming in patients with refractory or relapsed acute myeloid leukemia with translocation (8;21)

High expression levels of granulocyte colony stimulating factor (G-CSF) receptor were found in the leukemic cells of acute myeloid leukemia (AML) patients with t(8;21). Therapeutic significance of G-CSF receptor on chemotherapy remains to be defined. We evaluate the efficacy and tolerability of CAG regimen, consisting of concurrent use of G-CSF with low-dose cytarabine and aclarubicin, in 36 refractory/relapsed AML patients with t(8;21). The overall complete remission (CR) rate was 75% and median CR duration was 12 months. No significant treatment-related adverse events were observed. These data demonstrate that CAG regimen might be an alternative option in the treatment of AML with t(8;21), especially in older patients or patients with co-morbidities.

Successful treatment of Cisplatin overdose with plasma exchange

Accidental cisplatin overdose has been occurring with an increasing frequency due to expanding usage of the agent. However, the optimal strategy to treat such patients remains to be established. Here, we report a case of large cisplatin overdose, successfully managed by plasma exchange, intravenous hydration, granulocyte colony-stimulating factor (G-CSF) administration, and other supportive care. A 67-year-old man with esophageal carcinoma received a large cisplatin overdose of 240 mg/m², when he received adjuvant therapy following subtotal esophagectomy. On day 4, he experienced frank cisplatin toxicities and emergency plasma exchange was initiated. With 7 cycles of plasma exchange, the cisplatin concentration decreased from 2,350 to 110 ng/mL. Severe bone marrow suppression with high fever ensued on day 10, which was successfully treated with G-CSF and antibiotics. Despite moderate hearing sense reduction, he recovered without significant complications. Immediate plasma exchange with hydration and other care was efficacious in quickly lowering cisplatin concentrations.

Continuous drip infusion of low dose cytarabine and etoposide with granulocyte colony-stimulating factor for elderly patients with acute myeloid leukaemia ineligible for intensive chemotherapy

BACKGROUNDS AND OBJECTIVES

The optimal strategy for the management of elderly patients with acute myeloid leukaemia (AML) is still controversial. We previously reported the effectiveness of low dose cytarabine (Ara-C) and etoposide (VP-16) (AV therapy) for those elderly AML patients ineligible for intensive chemotherapy. We initiated the present feasibility study to improve the efficacy by using glanulocyte-colony stimulating factor (G-CSF) with AV therapy (AVG therapy).

PATIENTS AND METHODS

The eligibility for enrolment was AML patients according to the World Health Organization (WHO) criteria who were over 60 years of age and who had difficulty in tolerating intensive chemotherapy due to their poor performance status (PS) or some comorbidities. They were given continuous drip infusion of Ara-C (20 mg/body) and VP-16 (50 mg/body) for 7-14 days, and were also simultaneously administered G-CSF (150 microg/m2) once daily.

RESULTS

The median age of consecutively enrolled 25 patients was 73 years. Eighteen (72%) patients achieved complete remission (CR). The 1-year overall survival (OS) and the 3-year OS rates were 69% and 22%, respectively. The 1-year disease free survival (DFS) rate in CR patients was 44%. The major regimen related toxicities of grade 3 or 4 were only febrile neutropenia in 15 patients (60%). No regimen-related mortality was observed.

CONCLUSION

AVG therapy was therefore found to be an effective and well-tolerated regimen for remission induction in elderly AML patients with poor PS or comorbidity.

Combination chemotherapy with low-dose cytarabine, homoharringtonine, and granulocyte colony-stimulating factor priming in patients with relapsed or refractory acute myeloid leukemia

As sensitization of leukemic cells with granulocyte colony-stimulating factor (G-csf) can enhance the cytotoxicity of chemotherapy in acute myeloid leukemia (AML), a pilot study was conducted in order to evaluate the effect of G-csf priming combined with low-dose chemotherapy in patients with relapsed and refractory AML. The regimen, G-HA, consisted of cytarabine 7.5 mg/m2/12 hr by subcutaneous injection, days 1-14, homoharringtonine 1.5 mg/m2/day by intravenous continuous infusion, days 1-14, and G-csf 150 microg/m2/day by subcutaneous injection, days 0-14. Thirty-six AML patients were enrolled, 23 refractory and 13 relapsed. Eighteen patients (50%, 95% confidence interval: 33-67%) achieved complete remission (CR) with a median CR duration of 7.2 months, and two elderly patients continued a regimen of maintenance therapy and remained in remission for 26.3 and 14.1 months, respectively, as of last follow-up. Eight patients (22%) experienced neutropenia (median duration: 6 days; range: 2-22 days). Thirteen of the 36 (36%) developed severe infections. Grade 1-2 nonhematologic toxicities were documented, including nausea and vomiting (20%), liver function abnormality (6%), and heart function abnormality (6%). No central nervous system and kidney toxicity was observed. The G-HA regimen is effective in remission induction for refractory and relapsed AML patients and well tolerated in maintenance therapy in some subgroups of elderly patients. Further studies are necessary to elucidate optimum dose and schedule for this regimen to enhance the treatment efficacy of relapsed or refractory AML patients.

CAG regimen enables relapsed or refractory T-cell acute lymphocytic leukemia patients to achieve complete remission: a report of six cases

Patients with either relapsed or refractory T-cell acute lymphocytic leukemia (T-ALL) are candidates for allogeneic hematopoietic stem cell transplantation (allo-HSCT). Achieving complete remission (CR) in these patients is difficult but crucial for the success of allo-HSCT. In this study, we examined 6 relapsed or refractory T-ALL patients. In the patient group, 4 were male and 2 were female, with ages ranging from 15 to 57 years (median=29 years). All 6 patients presented with the nonmature T-ALL phenotype. Cytogenetically, only one had an i(7q) anomaly, whereas the remaining 5 cases had normal karyotypes. One of these patients had the MLL/AF9 fusion transcript, as shown by molecular study. After initial remission-induction therapy, two patients achieved CR, one showed a partial remission, and all relapsed soon. The other 3 cases failed the therapy. The CAG regimen (cytosine arabinoside 10 mg/m(2) subcutaneously every 12 hr, day 1-14; aclarubicin 5-7 mg/m(2) intravenously daily, day 1-8; and concurrent use of G-CSF 200 microg/m(2)/day subcutaneously) was devised originally for the treatment of relapsed acute myelogenous leukemia. After CAG therapy, all the T-ALL patients in our study achieved CR, indicating that the CAG regimen is beneficial to the treatment of relapsed or refractory T-ALL. The efficacy of CR-induction in T-ALL patients and the adverse effects of the CAG regimen need to be further studied.

Aclarubicin and low-dose Cytosine arabinoside in combination with granulocyte colony-stimulating factor in treating acute myeloid leukemia patients with relapsed or refractory disease and myelodysplastic syndrome: a multicenter study of 112 Chinese patients

One hundred twelve patients with geriatric acute myeloid leukemia (AML), refractory or relapsed AML, or myelodysplastic syndrome and refractory anemia with excess of blasts in transformation (MDS-RAEBt) were entered into this study to receive CAG (aclarubicin and low-dose cytosine arabinoside [Ara-C]in combination with granulocyte colony-stimulating factor [G-CSF]) with the objective of evaluating the efficacy and tolerance of this regimen. Low-dose Ara-C was given subcutaneously at a dosage of 10 mg/m2 every 12 hours on days 1 to 14. Aclarubicin was administered intravenously at a dosage of 14 mg/m2 per day on days 1 to 4 (CAG regimen A) or 7 mg/m2 on days 1 to 8 (CAG regimen B). Recombinant G-CSF was given subcutaneously at a dosage of 200 3g/m2 per day on days 1 to 14. We demonstrated comparable overall complete remission rates for the 4 groups of patients: 30.8% (8/26) in the elderly patients, 48.4% (30/62) in the refractory AML patients, 44.4% (8/18) in the relapsed AML patients, and 38.5% (5/13) in the MDS-RAEBt patients. Of the 52 patients followed up, the 12-month progression-free survival (PFS) and overall survival (OS) rates estimated by the Kaplan-Meier method were 40.73% 3 8.15% and 42.85% 3 8.23%, respectively. The median PFS and OS times were 9.0 3 2.2 months and 11.0 3 1.6 months, respectively. Toxic effects were very rare and mainly consisted of neutropenia and thrombocytopenia due to myelosuppression; approximately 70% to 80% of patients had neutropenia or thrombocytopenia that exceeded National Cancer Institute grade II. Nonhematologic toxicities were not observed in this study. The CAG regimen seems promising, with acceptable toxicity, for the treatment of various categories of poor-prognosis AML and MDS-RAEBt.

Granulocyte colony-stimulating factor enhances the in vitro cytotoxicity of gemtuzumab ozogamicin against acute myeloid leukemia cell lines and primary blast cells

OBJECTIVE

To evaluate the effects of granulocyte colony-stimulating factor (G-CSF) on the in vitro sensitivity of acute myeloid leukemia (AML) cell lines and primary AML blast cells to gemtuzumab ozogamicin (GO).

MATERIALS AND METHODS

AML cell lines and primary blasts from 10 patients with AML were first incubated for 72 hours in the presence of G-CSF (5 or 100 ng/mL) and then exposed to increasing concentrations of GO (1-1,000 ng/mL) for an additional 72 hours.

RESULTS

Pretreatment with G-CSF translated into significant enhancement of GO-induced cytotoxicity in the GO-sensitive HL-60 and NB-4 cells. Conversely, the response of GO-insensitive KG-1a, TF-1, and K562 cells was unaffected by in vitro priming with G-CSF. In vitro exposure to G-CSF augmented GO-induced apoptosis in 7 of 10 primary AML samples and rendered blast cells from three refractory patients sensitive to killing effect of GO. The G-CSF-induced increase of the cytocidal activity of GO was independent of effects on the cell cycle and on the expression levels of CD33 antigen. Of potential interest, G-CSF induced dose-dependent inhibition of P-glycoprotein (P-gp/ABCB1) function in the GO-sensitive HL-60 and NB-4 cells and in blasts from three patients with AML that we tested.

CONCLUSION

Collectively, our findings point to G-CSF as a potential sensitizing agent that can be exploited therapeutically to improve the clinical efficacy of GO.

Elevated levels of cyclin A1 and A (A2) mRNA in acute myeloid leukaemia are associated with increased survival

Cyclin A (A2) and cyclin A1 are members of the G2 cyclins, which are involved in the control of G2/M and G1/S transitions as well as mitosis. Human cyclin A1 was cloned as an A-type cyclin that is highly expressed in acute myeloid leukaemia (AML). The clinical significance of these cyclins in myeloid leukaemia remains to be clarified. We investigated the relative levels of these transcripts in 80 patients with de novo AML. Correlations with clinical parameters showed that the initial white blood cell count and serum lactate dehydrogenase levels were inversely associated with cyclin A (A2) mRNA levels (r = -0.276, P = 0.019) and cyclin A1 mRNA levels (r = -0.241, P = 0.042) respectively. They were independently associated with increased overall survival [P = 0.035 for cyclin A (A2) and P = 0.016 for cyclin A1]. Multivariate analysis using Cox's proportional hazard model showed that elevated cyclin A1 mRNA levels contributed significantly to the better prognosis of patients with AML. Furthermore, the analysis of survival probability showed that the group with high levels of both cyclin A (A2) and A1 survived significantly longer than the group with low expression of both these cyclins (P = 0.002). These data indicate that high expression levels of both cyclin A (A2) and A1 are associated with good prognosis in AML patients.

Cell proliferation is related to in vitro drug resistance in childhood acute leukaemia

Bone marrow and peripheral blood samples from 362 patients with acute lymphoblastic leukaemia (ALL) proliferating cell and 90 patients with acute myeloid leukaemia (AML) were analysed for S-phase fractions, Ki67 antigen, and proliferating cell nuclear antigen expression. The S-phase fractions were correlated with in vitro drug resistance to 15 different anticancer agents. Leukaemia cells isolated from bone marrow had higher S-phase fractions than leukaemia cells isolated from peripheral blood (in initial ALL, median values resp. 6.9 and 2.7%, in initial AML resp. 5.3 and 1.3%; both P<0.01). Relapse ALL samples derived from bone marrow showed increased S-phase fractions (median 9.9%) compared with initial ALL samples (median 6.9%; P<0.01). ALL samples obtained at initial diagnosis showed higher S-phase fractions (median 6.9%) and higher Ki67 expression (median 30%) than initial AML samples (median resp. 5.3 and 14%; both P<0.05). The S-phase fractions were not related to white blood cell count, age, or gender. Within initial ALL, the S-phase fraction correlated significantly but modestly strong (rho=0.3-0.5; P<0.05) with sensitivity to antimetabolites (cytarabine, mercaptopurine, thioguanine), L-asparaginase, teniposide, and vincristine. Similar results were found within subgroups of initial ALL (nonhyperdiploid and common/precursor-B-lineage ALL). In relapsed ALL and AML such correlations were not found. In conclusion, cell proliferation differs between leukaemia subgroups and increased proliferation is associated with increased in vitro sensitivity to several anticancer agents in initial ALL.

Use of marine toxins in combination with cytotoxic drugs for induction of apoptosis in acute myelogenous leukaemia cells

Intensive chemotherapy for acute myelogenous leukaemia (AML) results in an overall long-term disease-free survival of < 50%. This percentage reflects an improved survival for certain subsets of patients with low-risk cytogenetic abnormalities after treatment with high-dose cytarabine, whereas lower long-term survival is seen for other patients and especially for the large group of elderly patients. New treatment strategies are therefore considered in AML and one approach is to target the regulation of apoptosis in AML cells with new pharmacological agents. Regulation of apoptosis seems to be clinically important in AML as intracellular levels of apoptosis-regulating mediators can be used as predictors of prognosis in AML. It is also well documented that cytotoxic drugs exert important antileukaemic effects through induction of apoptosis. Marine toxins represent new pharmacological agents with proapoptotic effects and should be considered for combination therapy with cytotoxic drugs. These agents are already useful laboratory tools for in vitro studies of AML cells but it is still too early to conclude whether they will become useful in clinical therapy. One of the major problems to be investigated is the toxicity of combination therapy, although this may be solved by the coupling of toxins to antibodies or growth factors with a preferential binding to AML cells. Other problems that have to be addressed are the possible effect of the toxins' tumour promoting effects on chemosensitivity in relapsed AML and the possibility of cross-resistance between cytotoxic drugs and toxins.

Cyclopentenyl cytosine induces apoptosis and increases cytarabine-induced apoptosis in a T-lymphoblastic leukemic cell-line

Cyclopentenyl cytosine (CPEC) is a nucleoside-analogue that decreases the concentrations of cytidine triphosphate (CTP) and deoxycytidine triphosphate (dCTP) in leukemic cells by inhibiting the enzyme CTP synthetase, resulting in a decreased synthesis of RNA and DNA. Low concentrations of dCTP facilitate the phosphorylation of 1-beta-D arabinofuranosyl cytosine (araC) and the incorporation of arabinofuranosyl cytosine triphosphate (araCTP) into DNA. Apoptosis and necrosis were analyzed by flow cytometric detection of fluorescence-labeled Annexin V in a human T-lymphoblastic MOLT-3 cell-line after incubations with CPEC and/or araC. CPEC induced apoptosis and necrosis in a concentration- (50-300 nM) and time-dependent (8-16 h) way. The observed necrosis proved to be secondary to apoptosis as the caspase inhibitor benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone (zVAD-fmk) completely blocked the CPEC-induced apoptosis and necrosis. Coincubation of various concentrations of CPEC and araC for 16h showed a significant additive effect on the occurrence of apoptosis and (secondary) necrosis. In contrast, a preincubation with 37.5 nM of CPEC for 24 h, which by itself caused only minor apoptosis (4%), followed by a coincubation for 16 h with 62.5 nM of araC (7% of apoptotic cells), showed a synergistic effect on the induction of apoptosis (27%, P<0.001). Growth-inhibition experiments with CPEC and araC under various conditions showed an additive effect on the araC-induced growth-inhibition after 48 h. The results indicate that the cytotoxicity of araC can be increased in T-lymphoblasts by CPEC.

Current Perspectives on the Use of Growth Factors in the Therapy of Acute Myeloid Leukaemia; Malignancy

Recombinant haematopoietic growth factors have been available for clinical use for over a decade, however their role in the management of patients with acute myeloid leukaemia (AML) has yet to be established. There are several potential roles for the use of growth factors in the management of patients with AML, including reduction in the infective complications associated with the underlying disease and its treatment, use as mobilising agents in stem cell transplantation and as priming agents with chemotherapy. Clinical trials have failed to give clear indications for the use of growth factors following chemotherapy, mainly due to the variability of patient populations, chemotherapy and growth factor schedules used. G-CSF appears to be associated with no negative impact on remission rate or survival but clear benefits in terms of infection-related endpoints were not universally seen. Three studies did show a reduction in duration of hospitalisation, particularly when G-CSF was used following consolidation chemotherapy and economic analyses have also shown financial advantages to the administration of G-CSF. GM-CSF had a variable impact on survival and only two studies demonstrated reduction in serious infections or antimicrobial therapy use. These trials also showed economic benefits for the use of GM-CSF. Clinical studies which have attempted to exploit possible potentiation of chemotherapeutic activity by recruitment of leukaemic cells into the cell cycle have generally been disappointing. Use of growth factors for this purpose, outside the context of randomised clinical trials cannot be recommended. GM-CSF may have a role in modulating the cellular immune response against cancer cells but experimental data on its activity against leukaemia cells is limited. Augmentation of white cell function by G-CSF or GM-CSF may also be of clinical benefit in patients with suspected or confirmed fungal infection and further trials are underway.

Effect of granulocyte colony-stimulating factor on chemotherapeutic activity of cytosine arabinoside in acute leukemic cell lines

Recent studies have shown the presence of receptors for granulocyte colony-stimulating factor (G-CSF) on lymphoid leukemic cells. To determine the effect of G-CSF on chemotherapeutic activity of cytosine arabinoside (Ara-C) on lymphoid as well as myeloid leukemic cells, we evaluated cell counts, apoptosis, and growth inhibition in HL-60, KG-1, Molt-4, Jijoye, and CCRF-CEM cell lines after incubation with Ara-C (0.1 and 1 micromol/L) and/or 5 ng/mL G-CSE G-CSF potentiated the effect of Ara-C on 2 of 3 lymphoid leukemic cell lines (Molt-4 and Jijoye), whereas it decreased the apoptosis and the effect of Ara-C on myeloid cell lines (HL-60 and KG-1).

The CAG regimen (low-dose cytarabine, aclarubicin hydrochloride and granulocyte colony-stimulating factor) for the treatment of elderly acute myelomonocytic leukaemia: a case study

Elderly patients with acute myelomonocytic leukaemia (AMMoL) frequently have a poor quality of life after induction of remission using high-intensity treatment; we seek a more appropriate regimen for such patients. An 86-year-old man was hospitalized with a diagnosis of AMMoL (FAB classification M4), of abnormal karyotype, and complications of diabetes mellitus and complete right bundle branch block. He was treated with CAG therapy (cytarabine 10 mg/m2 subcutaneously every 12 h for 14 consecutive days; aclarubicin hydrochloride 10 mg/m2 per day, bolus intravenously for 4 consecutive days; granulocyte colony-stimulating factor 100 microg/day, subcutaneous injection for 14 consecutive days) every 3 months. White blood cell counts were at their lowest (around 600 - 800/microl) 12 days after the end of therapy, but returned to about 2000 - 2300/microl 30 days after stopping therapy. No symptoms of drug-related toxicity, except slight nausea, were found. Complete remission with a good quality of life was induced and lasted over 2 years suggesting that CAG therapy might prove effective in elderly patients with AMMoL.

Fas ligand, Bcl-2, granulocyte colony-stimulating factor, and p38 mitogen-activated protein kinase: Regulators of distinct cell death and survival pathways in granulocytes

The short life span of granulocytes, which limits many inflammatory responses, is thought to be influenced by the Bcl-2 protein family, death receptors such as CD95 (Fas/APO-1), stress-activated protein kinases such as p38 mitogen-activated protein kinase (MAPK), and proinflammatory cytokines like granulocyte colony-stimulating factor (G-CSF). To clarify the roles of these various regulators in granulocyte survival, we have investigated the spontaneous apoptosis of granulocytes in culture and that induced by Fas ligand or chemotherapeutic drugs, using cells from normal, CD95-deficient lpr, or vav-bcl-2 transgenic mice. CD95-induced apoptosis, which required receptor aggregation by recombinant Fas ligand or the membrane-bound ligand, was unaffected by G-CSF treatment or Bcl-2 overexpression. Conversely, spontaneous and drug-induced apoptosis occurred normally in lpr granulocytes but were suppressed by G-CSF treatment or Bcl-2 overexpression. Although activation of p38 MAPK has been implicated in granulocyte death, their apoptosis actually was markedly accelerated by specific inhibitors of this kinase. These results suggest that G-CSF promotes granulocyte survival largely through the Bcl-2-controlled pathway, whereas CD95 regulates a distinct pathway to apoptosis that is not required for either their spontaneous or drug-induced death. Moreover, p38 MAPK signaling contributes to granulocyte survival rather than their apoptosis.

Combination of granulocyte colony-stimulating factor and low-dose cytosine arabinoside further enhances myeloid differentiation in leukemia cells in vitro

We examined the differentiation-inducing effect on freshly isolated myeloid leukemia cells in liquid suspension culture by combined treatment with granulocyte colony-stimulating factor (G-CSF) plus low-dose cytosine arabinoside (Ara-C; 5-10 ng/ml) in 25 patients with acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) in leukemic transformation. Culture with G-CSF alone showed leukemic cell growth stimulation in 15 out of the 25 cases (60%) and induction of cell differentiation in 19 out of the 25 cases (76%), respectively. In 23 cases (92%), either growth stimulation and/or differentiation induction of leukemia cells was observed in response to G-CSF. This suggests that most myeloid leukemia cells are able to respond to G-CSF stimulation. In addition, treatment of cells with low-dose Ara-C alone resulted in the enhancement of myeloid specific antigens expression in 16 cases (64%). Treatment of leukemia cells with higher concentrations of Ara-C (over 50 ng/ml) alone resulted in cytocidal effects but not in the induction of differentiation. Furthermore, 15 cases (60%) showed pronounced myeloid differentiation of leukemia cells after combined exposure to G-CSF plus low-dose Ara-C as compared with cells treated with either G-CSF or Ara-C alone. The enhanced effect of differentiation induction by combining G-CSF plus low-dose Ara-C was also observed in a murine myeloid leukemia cell line WEHI-3B in vitro. These data suggest that treatment with G-CSF plus low-dose Ara-C is capable of inducing differentiation of leukemic cells in vitro, and also appears to be useful for the differentiation-based therapy of patients with AML and MDS.

Chronic myelomonocytic leukemia derived from a possible common progenitor of monocytes and natural killer cells

The neural cell adhesion molecule, CD56, is expressed on acute myelogenous leukemia (AML) cells in 17-20% of the patients. However, the clinical and biological significance of its expression in AML has not been well analyzed from the standpoint of CD56 expression and its association with differentiation to a natural killer (NK) cell lineage. Here we present a 78-year-old patient with chronic myelomonocytic leukemia (CMML) whose leukemic cells had features of both monocytes and NK cells. We demonstrated that the leukemic cells were positive for CD4, CD56 and interleukin-2 (IL-2) receptor beta chain (CD112) in addition to myelomonocytic markers such as CD33, CD11b and CD11c. These leukemic cells proliferated well in vitro in response to 10-100 U/ml of IL-2, and functionally showed significant cytotoxicity against K562 target cells in a 4-hour (51) Cr release assay. All the above data indicate that these cells possessed at least some of the biological features of NK cells. Accordingly, we speculate that the leukemic cells in this patient may have been derived from a possible common progenitor of monocytes and NK cells.

Priming effects of macrophage colony-stimulating factor on monocytic leukemia cells in combination with chemotherapy: induction of programmed cell death in vivo

Two elderly patients with chronic myelomonocytic leukemia were treated with cytosine arabinoside (Ara-C) and aclarubicin (ACR) under simultaneous administrations of macrophage colony-stimulating factor (M-CSF) (CAM), and both obtained good responses. Examination of apoptosis using flow cytometry revealed induction of apoptotic death of leukemia cells by CAM in Patient 2, while neither induction of apoptotic death of leukemia cells nor clinical response were seen with CAG (Ara-C, ACR, and granulocyte colony-stimulating factor) given prior to CAM in Patient 1. These findings suggested that chemotherapy combined with simultaneous administration of M-CSF could effectively reduce monocytic leukemia cells by inducing programmed cell death.