Background Heterodimeric methyltransferases GLP (EHMT1/KMT1D) and G9a (EHMT2/KMT1C) are two closely related enzymes that promote the monomethylation and dimethylation of histone H3 lysine 9. Dysregulation of their activity has been implicated in several types of human cancer. Patients and methods Here, in order to investigate whether GLP/G9a exerts any impact on Chronic Lymphocytic Leukemia (CLL), GLP/G9a expression levels were assessed in a cohort of 50 patients and the effects of their inhibition were verified for the viability of CLL cells. Also, qRT-PCR was used to investigate the transcriptional levels of GLP/G9a in CLL patients. In addition, patient samples were classified according to ZAP-70 protein expression by flow cytometry and according to karyotype integrity by cytogenetics analysis. Finally, a selective small molecule inhibitor for GLP/G9a was used to ascertain whether these methyltransferases influenced the viability of MEC-1 CLL cell lineage. Results mRNA analysis revealed that CLL samples had higher levels of GLP, but not G9a, when compared to non-leukemic controls. Interestingly, patients with unfavorable cytogenetics showed higher expression levels of GLP compared to patients with favorable karyotypes. More importantly, GLP/G9a inhibition markedly induced cell death in CLL cells. Conclusion Taken together, these results indicate that GLP is associated with a worse prognosis in CLL, and that the inhibition of GLP/G9a influences CLL cell viability. Altogether, the present data demonstrate that these methyltransferases can be potential markers for disease progression, as well as a promising epigenetic target for CLL treatment and the prevention of disease evolution.
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Rai KR, Jain P (2016) Chronic lymphocytic leukemia (CLL)-Then and now. Am J Hematol 91:330–340
Zenz T, Mertens D, Küppers R et al (2009) From pathogenesis to treatment of chronic lymphocytic leukaemia. Nat Rev Cancer 10:37–50
Rai KR, Sawitsky A, Cronkite EP et al (1975) Clinical staging of chronic lymphocytic leukemia. Blood 46:219–234
Binet JL, Auquier A, Dighiero G et al (1981) A new prognostic classification of chronic lymphocytic leukemia derived from a multivariate survival analysis. Cancer 48:198–206
Scarfò L, Ferreri AJM, Ghia P (2016) Chronic lymphocytic leukaemia. Crit Rev Oncol Hematol 104:169–182
Roos-Weil D, Nguyen-Khac F, Bernard OA (2016) Chronic lymphocytic leukemia: Time to go past genomics? Am J Hematol 91:518–528
Kurdistani SK (2007) Histone modifications as markers of cancer prognosis: a cellular view. Br J Cancer 97:1–5
Mozzetta C, Pontis J, Ait-Si-Ali S (2015) Functional Crosstalk Between Lysine Methyltransferases on Histone Substrates: The Case of G9A/GLP and Polycomb Repressive Complex 2. Antioxid Redox Signal 22:1365–1381
Matutes E, Owusu-Ankomah K, Morilla R et al (1994) The immunological profile of B-cell disorders and proposal of a scoring system for the diagnosis of CLL. Leukemia 8:1640–1645
Crespo M, Bosch F, Villamor N et al (2003) ZAP-70 Expression as a Surrogate for Immunoglobulin-Variable-Region Mutations in Chronic Lymphocytic Leukemia. N Engl J Med 348:1764–1775
Döhner H, Stilgenbauer S, Benner A et al (2000) Genomic Aberrations and Survival in Chronic Lymphocytic Leukemia. N Engl J Med 343:1910–1916
Nabhan C, Raca G, Wang YL (2015) Predicting Prognosis in Chronic Lymphocytic Leukemia in the Contemporary Era. JAMA Oncol 1:965–974
Mayr C, Speicher MR, Kofler DM et al (2006) Chromosomal translocations are associated with poor prognosis in chronic lymphocytic leukemia. Blood 107:742–751
Guièze R, Wu CJ (2015) Genomic and epigenomic heterogeneity in chronic lymphocytic leukemia. Blood 126:445–453
Shinkai Y, Tachibana M (2011) H3K9 methyltransferase G9a and the related molecule GLP. Genes Dev 25:781–788
Loh SW, Ng WL, Yeo KS et al (2014) Inhibition of euchromatic histone methyltransferase 1 and 2 sensitizes chronic myeloid leukemia cells to interferon treatment. PLoS One 9:e103915
Pappano WN, Guo J, He Y et al (2015) The Histone Methyltransferase Inhibitor A-366 Uncovers a Role for G9a/GLP in the Epigenetics of Leukemia. PLoS One 10:e0131716
Huang J, Dorsey J, Chuikov S et al (2010) G9a and Glp methylate lysine 373 in the tumor suppressor p53. J Biol Chem 285:9636–9641
Orchard JA, Ibbotson RE, Davis Z et al (2004) ZAP-70 expression and prognosis in chronic lymphocytic leukaemia. Lancet 363:105–111
Zenz T, Eichhorst B, Busch R et al (2010) TP53Mutation and Survival in Chronic Lymphocytic Leukemia. J Clin Oncol 28:4473–4479
Koníková E, Kusenda J (2003) Altered expression of p53 and MDM2 proteins in hematological malignancies. Neoplasma 50:31–40
Tomasini R, Mak TW, Melino G (2008) The impact of p53 and p73 on aneuploidy and cancer. Trends Cell Biol 18:244–252
Lazarian G, Tausch E, Eclache V et al (2016) TP53 mutations are early events in chronic lymphocytic leukemia disease progression and precede evolution to complex karyotypes. Int J Cancer 139:1759–1763
Dicker F, Herholz H, Schnittger S et al (2009) The detection of TP53 mutations in chronic lymphocytic leukemia independently predicts rapid disease progression and is highly correlated with a complex aberrant karyotype. Leukemia 23:117–124
Lin X, Huang Y, Zou Y et al (2016) Depletion of G9a gene induces cell apoptosis in human gastric carcinoma. Oncol Rep 35:3041–3049
Ren A, Qiu Y, Cui H, Fu G (2015) Inhibition of H3K9 methyltransferase G9a induces autophagy and apoptosis in oral squamous cell carcinoma. Biochem Biophys Res Commun 459:10–17
Li F, Zeng J, Gao Y et al (2015) G9a Inhibition Induces Autophagic Cell Death via AMPK/mTOR Pathway in Bladder Transitional Cell Carcinoma. PLoS One 10:e0138390
Lai Y-S, Chen J-Y, Tsai H-J et al (2015) The SUV39H1 inhibitor chaetocin induces differentiation and shows synergistic cytotoxicity with other epigenetic drugs in acute myeloid leukemia cells. Blood Cancer J 5:e313
This study was supported by Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) and Fundação de Amparo à Pesquisa do Distrito Federal (FAPDF).
Conflicts of Interest
The authors declare that they have no conflict of interest.
All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Declaration of Helsinki and its later amendments or comparable ethical standards.
Informed consent was obtained from all individual participants included in the study.
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Alves-Silva, J.C., de Carvalho, J.L., Rabello, D.A. et al. GLP overexpression is associated with poor prognosis in Chronic Lymphocytic Leukemia and its inhibition induces leukemic cell death. Invest New Drugs 36, 955–960 (2018). https://doi.org/10.1007/s10637-018-0613-x
- Chronic lymphocytic leukemia
- Prognostic marker, cytogenetic abnormalities