Title: Correlation of Neuron-Glial Antigen 2 (NG2) Expression to MLL Gene Rearrangements in Acute Lymphoblastic Leukemia
Authors: Hanaa Mohamed Afifi, Gehan Mostafa Hamed, Esraa Maonsour Shehata
DOI: http://dx.doi.org/10.18535/jmscr/v4i6.43
Abstract
Background: Acute lymphoblastic leukemias (ALL) carrying a chromosomal translocation involving the mixed-lineage leukemia gene (MLL) has a particularly poor prognosis. The presence of the MLL translocation often results in an early relapse after chemotherapy. For this reason, the accurate detection of MLL rearrangements (MLL-r) is crucial when dealing with this aggressive type of leukemia. We determined the correlation of the surface antigen neuron-glial antigen 2 (NG2) to the presence of MLL-r, and its value as a rapid inexpensive method for prediction of MLL-r at diagnosis of ALL patients.
Methods: 44 newly diagnosed children with ALL were studied for the presence of MLL rearrangement by fluorescence in situ hybridization (FISH), as well as measurement of NG2 expression by flow cytomery.
Results: MLL-r was successfully detected in 16 (36.4%) patients, while NG2 expression was positive in 14 (31.8%) patients. A positive correlation was found between NG2 expression and MLL–r (r=0.531, p<0.001), receiver operating characteristic curve (ROC) analysis revealed that NG2 value ≥ 18.6% could predict the presence of MLL-r with 85% sensitivity, 95% specificity, and 90% accuracy (p=0.004). Hyperleucocytosis, high lactate dehydrogenase (LDH) level, and presence of central nervous system (CNS) infiltration were significantly higher in patients with MLL-r and positive NG2 expression compared with MLL-r negative and NG2 negative ALL patients (p<0.001).
In conclusion, immunophenotypic analysis of NG2 expression with a cutoff value ≥ 18.6% allows the identification and prediction of MLL-r, with high specificity and accuracy suggesting that flow cytometry is a reliable, cost-effective and rapid tool for detection of MLL-r.
Keywords: ALL, NG2 expression, MLL rearrangements.
References
1. Pui CH, Robison LL, Look AT. Acute lymphoblastic leukaemia. Lancet 2008;371:1030–43.
2. Marchesi E, Girardi K, Avvisati G. Pathogenetic, clinical, and prognostic features of adult (4;11)(q21;q23)/MLL-AF4 positive B-cell acute lymphoblastic leukemia. Adv Hematol 2011;2011:621-7.
3. Wuchter C, Harbott J, Schoch C, Schnittger S, Borkhardt A, Karawajew L, Ratei R, Ruppert V, Haferlach T, Creutzig U, Dörken B, Ludwig WD. Detection of acute leukemia cells with mixed lineage leukemia (MLL) gene rearrangements by flow cytometry using monoclonal antibody NG2. Leukemia 2000;14:1232-8.
4. Meyer C, Kowarz E, Hofmann J, Renneville A, Zuna J, Trka J, Ben Abdelali R, Macintyre E, De Braekeleer E, De Braekeleer M, Delabesse E. New insights to the MLL recombinome of acute leukemias. Leukemia 2009;23:1490–9.
5. Burmeister T, Meyer C, Schwartz S, Hofmann J, Molkentin M, Kowarz E, Schneider B, Raff T, Reinhardt R, Gökbuget N, Hoelzer D. The MLL recombinome of adult CD10-negative B-cell precursor acute lymphoblastic leukemia results from the GMALL study group. Blood 2009;113:4011–5.
6. Pieters R, Schrappe M, De Lorenzo P, Hann I, De Rossi G, Felice M, Hovi L, LeBlanc T, Szczepanski T, Ferster A, Janka G. A treatment protocol for infants younger than 1 year with acute lymphoblastic leukaemia (Interfant-99): an observational study and a multicentre randomized trial. Lancet 2007;370:240–50
7. van der Linden MH, Valsecchi MG, De Lorenzo P, Möricke A, Janka G, Leblanc TM, Felice M, Biondi A, Campbell M, Hann I, Rubnitz JE. Outcome of congenital acute lymphoblastic leukemia treated on the Interfant-99 protocol. Blood 2009;114:3764–8.
8. Tomizawa D, Koh K, Sato T, Kinukawa N, Morimoto A, Isoyama K, Kosaka Y, Oda T, Oda M, Hayashi Y, Eguchi M. Outcome of risk-based therapy for infant acute lymphoblastic leukemia with or without an MLL gene rearrangement, with emphasis on late effects: a final report of two consecutive studies, MLL96 and MLL98, of the Japan Infant Leukemia Study Group. Leukemia 2007;21:2258–63.
9. Behm FG, Smith FO, Raimondi SC, Pui CH, Bernstein ID. Human homologue of the rat chondroitin sulfate proteoglycan, NG2, detected by monoclonal antibody 7. 1, identifies childhood acute lymphoblastic leukemias with t(4;11)(q21;q23) or t(11;19)(q23;p13) and MLL gene rearrangements. Blood 1996;87:1134–9.
10. Hilden JM, Smith FO, Frestedt JL, McGlennen R, Howells WB, Sorensen PH, Arthur DC, Woods WG, Buckley J, Bernstein ID, Kersey JH. MLL gene rearrangement, cytogenetic 11q23 abnormalities, and expression of the NG2 molecule in infant acute myeloid leukemia. Blood 1997;89:3801–5.
11. Smith FO, Rauch C, Williams DE, March CJ, Arthur D, Hilden J, Lampkin BC, Buckley JD, Buckley CV, Woods WG, Dinndorf PA. The human homologue of rat NG2, a chondroitin sulfate proteoglycan, is not expressed on the cell surface of normal hematopoietic cells but is expressed by acute myeloid leukemia blasts from poor-prognosis patients with abnormalities of chromosome band 11q23. Blood 1996;87:1123–33.
12. Wuchter C, Harbott J, Schoch C, Schnittger S, Borkhardt A, Karawajew L, Ratei R, Ruppert V, Haferlach T, Creutzig U, Dorken B. Detection of acute leukemia cells with mixed lineage leukemia (MLL) gene rearrangements by flow cytometry using monoclonal antibody 7.1. Leukemia 2000;14:1232–8.
13. Bueno C, Montes R, Martin L, Prat I, Hernandez MC, Orfao A, Menendez P. NG2 antigen is expressed in CD34+ HPCs and plasmacytoid dendritic cell precursors: is NG2 expression in leukemia dependent on the target cell where leukemogenesis is triggered? Leukemia 2008;22:1475–8.
14. Emerenciano M, Renaud G, Sant’Ana M, Barbieria C, Passetti F and Pombo-de-Oliveira M. Challenges in the use of NG2 antigen as a marker to predict MLL rearrangements in multi-center studies. Leukemia Research 2011;35: 1001-1007.
15. Bueno C, Montes R, Catalina P, Rodriguez R, Menendez P. Insights into the cellular origin and etiology of the infant pro-B acute lymphoblastic leukemia with MLL-AF4 rearrangement. Leukemia 2011;25:400–10.
16. Vardiman JW, Thiele J, Arber DA, Brunning RD, Borowitz MJ, Porwit A, Harris NL, Le Beau MM, Hellström-Lindberg E, Tefferi A, Bloomfield CD. The 2008 revision of the World Health Organization (WHO) classification of myeloid neoplasms and acute leukemia: rationale and important changes. Blood. 2009;114:937–951.
17. Hopman AH, Voorter CE, Ramaekers FC. Detection of genomic changes in cancer by in situ hybridization. Mol Biol Rep 1994;19:31–44.
18. Meyer C, Schneider B, Jackob S. The MLL recombinome of acute leukemias. Leuk 2006;20:777-784.
19. Ayton P M, Cleary ML. Molecular mechanism of leukemogenesis mediated by MLL fusion proteins. Oncogen 2001;20:5695-5707.
20. Sam TN, Kersey JH, Linabery AM, Johnson KJ, Heerema NA, Hilden JM, Davies SM, Reaman GH, Ross JA. MLL gene rearrangements in infant leukemia vary with age at diagnosis and selected demographic factors: a Children's Oncology Group (COG) study. Pediatric blood and cancer 2012;58: 836-839.
21. Borwitz MJ, Chan JK. B lymphoblastic leukemia/ lymphoma with recurrent genetic abnormalities. In: WHO classification of tumors of hematopoietic and lymphatic tissue. Steven H, Elias C, Nancy L, ELanta S J, Stetano A, Harald S, Jurgen T and James W (eds). 4th edition. 2008. Chapter 9. P.P: 171-175. International Agency for Research on Cancer. Lyon, France.
22. Schwartz S, Rieder H, Schl¨ager B, Burmeister T, Fischer L, Thiel E. Expression of the human homologue of rat NG2 in adult acute lymphoblastic leukemia: close association with MLL rearrangement and a CD10(-)/CD24(-)/CD65s(+)/ CD15(+) B-cell phenotype. Leukemia 2003;17:1589–1595.
23. Kosaka Y, Koh K, Kinukawa N, Wakazono Y, Isoyama K, Oda T, Hayashi Y, Ohta S, Moritake H, Oda M, Nagatoshi Y, Kigasawa H, Ishida Y, Ohara A, Hanada R, Sako M, Sato T, Mizutani S, Horibe K, Ishii E. Infant acute lymphoblastic leukemia with MLL gene rearrangements: outcome following intensive chemotherapy and hematopoietic stem cell transplantation. Blood 2004;104:3527-3534