homoharringtonine and Leukemia--Monocytic--Acute

The aim of this study was to explore the clinical efficiency and side effects of GHA-priming therapy on patients with acute monocytic leukemia, and to analyze its mechanism. 37 patients with refractory, relapse, hypocellular acute monocytic leukemia and elderly patients with AML-M(5) were treated with GHA-priming therapy (G-CSF, homoharringtonine and low dosage of cytarabine). Clinical efficiency, side effects, and therapy-relevant mortality were observed. By using U937 cell line as in vitro model, effect of G-CSF on cell cycle was determined by propidium iodide staining method. The inhibition rate, apoptosis rate of U937 cell line treated with various combination of G-CSF, homoharringtonine and cytarabine were detected by flow cytometry. The expression of MLAA34 on U937 before or after treating with chemotherapy was analyzed by immunohistochemical method. The results showed that in all the 37 patients, the total remission rate was 62.2% [complete remission rate was 45.95% (17/37) and partial remission rate was 16.2% (6/37)]. The incidence of granulocyte deficiency was 18.92% (2/37) with median time of 4 days. The severe infection occurred in 2 cases. No severe bleeding, no mild digestive effect occurred. Other non-hematological toxicities were low in vitro when incubated with G-CSF for 24 hours, the S-phase cells obviously increased. The inhibition rate, apoptosis rate and expression of MLAA34 of U937 cells treated by GHA significantly decreased as compared with cells treated with HA. It is concluded that the GHA priming therapy can be used to treat patients with refractory, relapse, senile and hypocellular acute monocytic leukemia with satisfied response rate and low hematological and non-hematological toxicities. G-CSF can enhance cytotoxicity of drugs such as Ara-C and HHT by promoting G(0) phase cells into the reproductive cycle. GHA and HA therapy can inhibit cell proliferation, induce apoptosis, and the former has a more significant function. GHA priming therapy can down regulate the expression of MLAA 34. MLAA-34 is a novel anti-apoptotic factor of acute monocytic leukemia.

Topics: Adolescent; Adult; Aged; Antineoplastic Combined Chemotherapy Protocols; Cytarabine; Female; Granulocyte Colony-Stimulating Factor; Harringtonines; Homoharringtonine; Humans; Leukemia, Monocytic, Acute; Male; Middle Aged; Treatment Outcome; U937 Cells; Young Adult

To investigate the potentiated effects of total saponins of Panax Ginseng (TSPG) on inhibition of leukemic progenitor cells by cytotoxic drugs in acute myelocytic leukemia.. Using bone marrow culture of colony forming unite-acute myeloid leukemia (CFU-AML) method, the sensitivity of leukemic cells obtained from 18 patients to homoharringtonin (HHr), cytarabine (Ara), adriamycin (Adr) and etoposide (VP-16) were detected separately.. TSPG alone (20 micrograms/ml) could stimulate proliferation of CFU-AML obviously, and increase the colony numbers by 37.98% over the non-TSPG control (P < 0.01). In the presence of TSPG, the inhibition rates of CFU-AML of HHr, Ara, Adr and VP-16 were 51.2%-62.0% respectively, which were significantly higher than 30.4%-47.4% of non-TSPG control (all P < 0.01). In the combination of TSPG with cytotoxic drugs, the leukemic progenitor cells became more sensitive to cytotoxic drugs, CFU-AML colony numbers at 1.84-2.23 fold as more as those of non-TSPG control were inhibited by HHr, Ara, Adr and VP-16. Sensitivity test of 17 among 72 drugs reversed from resistant (suppression rate less than 30%) to sensitive (suppression rate more than 30%) by TSPG.. TSPG could drive non-cycling leukemic progenitors to enter cell cycle, and thereby enhance their susceptibility to cytotoxic drugs.

Topics: Adult; Aged; Antineoplastic Agents; Antineoplastic Agents, Phytogenic; Drug Resistance, Neoplasm; Drug Synergism; Female; Ginsenosides; Harringtonines; Homoharringtonine; Humans; Leukemia, Monocytic, Acute; Leukemia, Myeloid, Acute; Leukemia, Promyelocytic, Acute; Male; Middle Aged; Panax; Saponins; Tumor Cells, Cultured; Tumor Stem Cell Assay