Studies from University of Perugia, Italy, advance leukemia knowledge

02-16-2007

Leukemia study results from University of Perugia, Italy, were highlighted recently in medical journals.

Study 1: Current study results from the report, "Chronic lymphocytic leukaemia Is terminal del(14)(q24) a new marker for prognostic stratification," have been published. "In a patient with chronic lymphocytic leukemia (CLL) molecular cytogenetics showed terminal del(14)(q24). Fluorescence in situ hybridisation (FISH) narrowed the deletion to a 35 megabases DNA segment, with the proximal breakpoint between two partially overlapping clones, RP1-116J24 and RP5-1119N5," scientists in Perugia, Italy report.

"Besides loss of material at 14q24-qter, comparative genomic hybridisation (CGH) showed loss of 3p21.3-pter, 4p11-p15.1, 8p12-pter, 13q12-q14, and 15q11-q15, and gain of 3q25-qter. Del(13)(q12-14) included the RB-1 gene but not D13S319 and D13S25 loci. The patient was refractory to fludarabine and rituximab," wrote Starza R. La and colleagues, University of Perugia.

The researchers concluded: "Our findings and data from other reports suggest del(14)(q24) is indicative of aggressive course and is closely associated with del(13)(q14) in CLL."

La and colleagues published their study in Leukemia Research (Chronic lymphocytic leukaemia Is terminal del(14)(q24) a new marker for prognostic stratification?. Leukemia Research, 2006;30(12):1569-72).

For additional information, contact R. La Starza, University of Perugia, Hematology and Bone Marrow Transplantation Unit, Perugia, Italy.

Study 2: Leukemia progression could be inhibited by virgin olive oil phenols.

"Although epidemiologic evidence and animal studies suggest that olive oil may prevent the onset of cancer, the components responsible for such an effect and their mechanisms of action remain largely unknown. In the present study, we investigated the effect of a virgin olive oil phenol extract (PE) on proliferation, the cell cycle distribution profile, apoptosis, and differentiation of the human promyelocytic cell line HL60," scientists in Italy reported.

"PE inhibited HL60 cell proliferation in a time- and concentration-dependent manner, as demonstrated by the viable cell count and 3-[4,5-dimethyl(thiazol-2yl)]-3,5-diphenyltetrazolium bromide (MTT) metabolism. Cell growth was completely blocked at a PE concentration of 13.5 mg/L; apoptosis was also induced as detected by fluorescence microscopy and flow cytometry," explained R. Fabiani and colleagues, University of Perugia.

"Determination of the cell cycle distribution by flow cytometry revealed an accumulation of cells in the G(0)/G(1) phase. Two compounds isolated from PE, the dialdehydic forms of elenoic acid linked to hydroxytyrosol (3,4-DHPEA-EDA) and to tyrosol (pHPEA-EDA), were shown to possess properties similar to those of PE; they account for a part of the powerful effects exerted by the complex mixture of compounds present in PE.

"The concentrations of the different compounds in PE were determined by HPLC, and the purity of 3,4-DHPEA-EDA and pHPEA-EDA was ascertained by NMR. Treatment with PE induced a differentiation in HL60 cells, which subsequently acquired the ability to produce superoxide ions and reduce nitroblue tetrazolium to formazan," remarked the investigative team.

The researchers concluded, "These results support the hypothesis that polyphenols play a critical role in the anticancer activity of olive oil."

Fabiani and colleagues published their study in the Journal of Nutrition (Virgin olive oil phenols inhibit proliferation of human promyelocytic leukemia cells (HL60) by inducing apoptosis and differentiation. J Nutr, 2006;136(3):614-619).

For additional information, contact G. Morozzi, University of Perugia, Dipartimento Specialita Med Chirurg & Sanita Pubb, Sez Epidemiology Molecular & Igiene Ambientale, I-06100 Perugia, Italy.

Study 3: A denaturing high-performance liquid chromatography (DHPLC) assay could be used to identify NPM1 mutations in leukemia.

According to recent research from Italy, "NPM1 gene mutations are the most frequent genetic lesion in the 60% of adult acute myeloid leukemias (AMLs) with normal karyotype and no evidence of typical fusion genes (BCR/ABL1, PML/RARA, AML1/ETO, CBFB/MYH11, DEK/CAN). Using direct sequencing we previously identified six different heterozygous mutants within exon 12 encoding the nucleophosmin C-terminus."

"Because of these mutations the shuttling protein nucleophosmin is aberrantly delocalized in the cytoplasm of leukemic cells (NPMc+)," explained G. Roti and colleagues, University of Perugia. "Here, we designed and tested a DHPLC assay to detect NPM1 mutated variants. To assess specificity, sensitivity, reliability, and reproducibility, we analyzed DNA from 120 primary adult AMLs and compared DHPLC results with immunohistochemistry and sequencing.

"All electropherogram profiles in the 26 NPMc+ leukemias were different from the wild type, indicating 100% sensitivity. Sequencing categorized mutations A, B, and D, and all mutation A cases gave identical elution profiles. The other mutations showed typical chromatograms, with mutations B and D differing for one nucleotide. Elution profiles and sequencing also identified four new variants."

The researchers concluded, "Our results suggest that DHPLC detects NPM1 mutations as well as direct sequencing and immunohistochemistry, providing a helpful approach in the diagnosis of NPMc+ AML."

Roti and colleagues published their study in the Journal of Molecular Diagnostics (Denaturing high-performance liquid chromatography - A valid approach for identifying NPM1 mutations in acute myeloid leukemia. J Mol Diagn, 2006;8(2):254-259).

For additional information, contact C. Mecucci, University of Perugia, Laboratory of Cytogenetics and Molecular Genetics, I-06123 Perugia, Italy.

This article was prepared by Hematology Week editors from staff and other reports. Copyright 2007, Hematology Week via NewsRx.com.