isotretinoin and Leukemia--Myelomonocytic--Chronic

The effective treatment for juvenile myelomonocytic leukemia (JMML) patients lacking access to stem cell transplantation remains unavailable. Here, we describe a promising result obtained with novel regimen comprised of a combination of chemotherapy and differentiation therapy. Five patients diagnosed as JMML were treated with a standard regimen (cytosine arabinoside (Ara-C) 100mg/m(2) per day continuous infusion (days 0-6), etoposide 100mg/m(2) per day (days 0-4), vincristine 1.5mg/m(2) per d (day 9) and isotretinoin 75-100mg/m(2) per day (days 10-20)). All patients responded to the standard regimen. Three of the five were later treated with salvage a regimen (Ara-C 100mg/m(2) per day continuous infusion (days 0-4), etoposide 100mg/m(2) per day (days 0-4) and Ara-C 15mg/m(2) per day SC (days 6-15)) when immature myeloid cells reappeared in the peripheral blood, the spleen increased or blast crisis occurred. Immature myeloid cells disappeared again after one cycle of salvage regimen in all patients. All patients are alive now with a median follow up duration of 27 months (8-69 months). Although the number of patients enrolled was limited, the standard and salvage regimens were found to be safe and effective alternatives for JMML patients without a matched donor. These regimens also could be used safely before stem cell transplantation.

Topics: Algorithms; Antineoplastic Combined Chemotherapy Protocols; Cytarabine; Etoposide; Female; Humans; Infant; Isotretinoin; Leukemia, Myelomonocytic, Chronic; Male; Salvage Therapy; Survival Rate; Treatment Outcome; Vincristine

Thirty-four patients with myelodysplastic syndromes, 23 men and 11 women, aged between 47 and 80 years, with all types of myelodysplastic syndromes were treated with 13-cis-retinoic acid. The dose of retinoic acid ranged between 10 and 60 mg/m2/daily and was administered in combination with vitamin E to diminish side effects. The duration of treatment was 3 months to 5 years. Partial remission was achieved in 4 patients, 1 with RA type, 2 with RAEB and 1 with CMML. Survival ranged from 1 to 5 years. Patients who received retinoic acid developed mild side effects. In conclusion, the administration of 13-cis-retinoic acid improves the hematological picture in a small number of MDS patients (11.7%).

Topics: Aged; Anemia, Refractory; Female; Humans; Isotretinoin; Leukemia, Myelomonocytic, Chronic; Male; Middle Aged; Myelodysplastic Syndromes; Survival Rate; Time Factors; Vitamin E

We recently synthesized several conformationally constrained retinoic acid (RA) analogues [8-(2'-cyclohexen-1'-ylidene)-3, 7-dimethyl-2,4,6-octatrienoic acids with different alkyl substituents at 2' (R1) and 3' (R2) positions on the cyclohexene ring] (Muccio et al. J. Med. Chem. 1996, 39, 3625) as cancer chemopreventive agents. UAB8 (R1 = Et; R2 = iPr), which contains sufficient steric bulk at the terminal end of the polyene chain to mimic the trimethylcyclohexenyl ring of RA, displayed biological properties similar to those of RA. To explore the efficacy of this retinoid in acute promyelocytic leukemia (APL) and juvenile myelomonocytic leukemia (JMML), we evaluated UAB8 isomers in in vitro assays which measure the capacity of retinoids to inhibit aberrant myeloid colony growth from blood or bone marrow cells obtained from human JMML patients and in assays measuring the potential of retinoids to differentiate NB4 cells (an APL cell line). Both (all-E)- and (13Z)-UAB8 were 2-fold more active than RA in the NB4 cell differentiation assay; however, only (all-E)-UAB8 had comparable activity to the natural retinoids in the JMML cell assays. These results were compared to the biological effectiveness of a new retinoid, UAB30 [8-(3', 4'-dihydro-1'(2'H)-naphthalen-1'-ylidene)-3,7-dimethyl-2,4, 6-octatrienoic acid], which had different nuclear receptor binding and transactivational properties than UAB8. Relative to (all-E)-RA and (all-E)-UAB8, (all-E)-UAB30 bound well to RARalpha but did not activate transcription-mediated RARalpha homodimers, even though it was effective in RARbeta- and RARgamma-mediated transactivational assays. In APL assays, this retinoid had much reduced activity and was only moderately effective in JMML assays and in cancer chemoprevention assays.

Topics: Animals; Antineoplastic Agents; Cell Line; Chickens; Child; Fatty Acids, Unsaturated; HL-60 Cells; Humans; In Vitro Techniques; Leukemia, Myelomonocytic, Chronic; Leukemia, Promyelocytic, Acute; Mice; Molecular Conformation; Naphthalenes; Papilloma; Radioligand Assay; Receptors, Retinoic Acid; Skin; Skin Neoplasms; Stereoisomerism; Transcription, Genetic; Tretinoin; Tumor Stem Cell Assay