Stewart DJ, Issa JP, Kurzrock R, Nunez MI, Jelinek J, Hong D, Oki Y, Guo Z, Gupta S, Wistuba II. Decitabine effect on tumor global DNA methylation and other parameters in a phase I trial in refractory solid tumors and lymphomas.
Clin Cancer Res 2009;
15:3881-8. [PMID:
19470736 DOI:
10.1158/1078-0432.ccr-08-2196]
[Citation(s) in RCA: 101] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
PURPOSE
By hypomethylating genes, decitabine may up-regulate factors required for chemotherapeutic cytotoxicity. Platinum-resistant cells may have reduced expression of the copper/platinum transporter CTR1.
EXPERIMENTAL DESIGN
Thirty-one patients with refractory malignancies received decitabine 2.5 to 10 mg/m(2) on days 1 to 5, and 8 to 12 or 15 to 20 mg/m(2) on days 1 to 5. Tumor was assessed for DNA methylation (by LINE assays), apoptosis, necrosis, mitoses, Ki67, DNA methyltransferase (DNMT1), CTR1, and p16.
RESULTS
Febrile neutropenia was dose limiting. One thymoma patient responded. Decitabine decreased tumor DNA methylation (from median 51.2% predecitabine to 43.7% postdecitabine; P = 0.01, with effects at all doses) and in peripheral blood mononuclear cells (from 65.3-56.0%). There was no correlation between tumor and peripheral blood mononuclear cells. Patients starting decitabine < or =3 versus >3 months after last prior cytotoxic or targeted therapy had lower predecitabine tumor CTR1 scores (P = 0.02), higher p16 (P = 0.04), and trends (P = 0.07) toward higher tumor methylation and apoptosis. Decitabine decreased tumor DNMT1 for scores initially >0 (P = 0.04). Decitabine increased tumor apoptosis (P < 0.05), mitoses (if initially low, P = 0.02), and CTR1 (if initially low, P = 0.025, or if < or =3 months from last prior therapy, P = 0.04). Tumor CTR1 scores correlated inversely with methylation (r = -0.41, P = 0.005), but CTR1 promoter was not hypermethylated. Only three patients had tumor p16 promoter hypermethylation. P16 scores did not increase. Higher blood pressure correlated with lower tumor necrosis (P = 0.03) and a trend toward greater DNA demethylation (P = 0.10).
CONCLUSIONS
Exposure to various cytotoxic and targeted agents might generate broad pleiotropic resistance by reducing CTR1 and other transporters. Decitabine decreases DNA methylation and augments CTR1 expression through methylation-independent mechanisms.
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