Granulocyte-colony stimulating factor induces differentiation and apoptosis of CD2, CD7 positive hybrid leukemia cells in vivo and ex vivo

Hypoplastic acute myeloid leukemia in an elderly patient. A long-term partial remission with low-dose prednisone and G-CSF

Hypoplastic acute myeloid leukemia (AML) is a rare variant of AML that mainly affects the elderly and accounts for 5%-7% of de novo AML. Prognosis for this disease is poor, and there is no standard therapy. We have treated an elderly patient with hypoplastic AML with low-dose prednisone and G-CSF with good results. We propose that this treatment may be a viable alternative to supportive therapy alone, or the tenuous chemotherapeutic challenge to elderly patients with hypoplastic AML.

Successful treatment of childhood hypocellular acute myeloid leukemia

Hypocellular acute myeloid leukemia (AML) is extremely rare in childhood. We report on a 7-year-old girl with hypocellular AML who was treated successfully with granulocyte-colony stimulating factor (G-CSF) and combined chemotherapy. High-dose G-CSF induced complete remission and she subsequently received reduced intensity conditioning and unrelated cord blood transplantation; however, this resulted in early rejection. After a complete hematological recovery, she received 3 courses of combination chemotherapy oriented toward AML. She has remained in complete remission for over 1 year after the completion of the therapy. G-CSF effectively induced remission, and combination chemotherapy has been proven to be feasible for patients with childhood hypocellular AML.

Hematological Remission and Long Term Hematological Control of Acute Myeloblastic Leukemia Induced and Maintained by Granulocyte-colony Stimulating Factor (G-CSF) Therapy

We describe a case of a patient with CD34+, TdT+, CD13-, CD33-, MPO- undifferentiated acute leukemia who refused chemotherapy and who achieved complete hematological remission 14 months after the diagnosis, during a short course of granulocyte-colony stimulating factor (G-CSF) for neutropenia and life threatening infection. Relapse occurred approximately one year later and G-CSF was reintroduced, being maintained for 4 months, at a dose and frequency adapted to maintain normal blood counts, a complete hematological remission being achieved again. Five months after withdrawing the G-CSF therapy a second relapse was observed; G-CSF was tried again with success, resulting in a very good hematological response that was sustained by G-CSF maintenance therapy. One year latter there was the need of increasing the doses of G-CSF in order to obtain the same hematological effect, at same time blast cells acquired a more mature CD34+, TdT-, CD13+, CD33-, MPO+ myeloid phenotype. Finally, the patient developed progressive neutropenia, anemia, thrombocytopenia and acute leukemia in spite of G-CSF therapy, dying 64 months after initial diagnosis (50 months after starting G-CSF therapy) with overt G-CSF resistant acute myeloblastic leukemia (AML), after failure of conventional induction chemotherapy.

Differentiation therapy of leukemia: 3 decades of development

A characteristic feature of leukemia cells is a blockade of differentiation at a distinct stage in cellular maturation. In the 1970s and 1980s, studies demonstrating the capabilities of certain chemicals to induce differentiation of hematopoietic cell lines fostered the concept of treating leukemia by forcing malignant cells to undergo terminal differentiation instead of killing them through cytotoxicity. The first promising reports on this notion prompted a review article on this subject by us 25 years ago. In this review, we revisit this interesting field of study and report the progress achieved in the course of nearly 3 decades. The best proof of principle for differentiation therapy has been the treatment of acute promyelocytic leukemia with all-trans retinoic acid. Attempts to emulate this success with other nuclear hormone ligands such as vitamin D compounds and PPARgamma agonists or different classes of substances such as hematopoietic cytokines or compounds affecting the epigenetic landscape have not been successful on a broad scale. However, a multitude of studies demonstrating partial progress and improvements and, finally, the new powerful possibilities of forward and reverse engineering of differentiation pathways by manipulation of transcription factors support the continued enthusiasm for differentiation therapy of leukemia in the future.

Effect of low-dose cytarabine and aclarubicin in combination with granulocyte colony-stimulating factor priming (CAG regimen) on the outcome of elderly patients with acute myeloid leukemia

The aim of this study was to evaluate the efficacy and toxicity of low-dose cytarabine and aclarubicin in combination with granulocyte colony-stimulating factor (G-CSF) protocol in elderly patients with acute myeloid leukemia (AML). A total of 50 elderly patients including 8 aged over 70 years were enrolled. All patients were treated with CAG regimen including low-dose cytarabine (10mg/m(2) every 12h, days 1-14), aclarubicin (10mg every day, days 1-8), and G-CSF (200 microg/m(2) every day, days 1-14) priming. The overall response rate was 72.0%, and 29 of 50 (58.0%) patients achieved complete remission, including 23 of 35 (65.8%) with previously untreated AML, 6 of 15 (40.0%) with refractory, relapsed or secondary AML, 4 of 8 (50.0%) aged over 70 years, 4 of 10 (40.0%) with unfavorable cytogenetic aberrations. The early death rate was 7.6%. The median overall survival was 14 months. Myelosuppression was mild to moderate, severe nonhematologic toxicity was not observed. Thus CAG priming regimen as the induction therapy is well tolerated and effective in elderly patients with AML.

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).