Methylation of death-associated protein kinase is associated with cetuximab and erlotinib resistance

Abstract

Anti-EGFR therapy is among the most promising molecular targeted therapies against cancer developed in the past decade. However, drug resistance eventually arises in most, if not all, treated patients. Emerging evidence has linked epigenetic changes, such as DNA methylation at CpG islands, to the development of resistance to multiple anticancer drugs. In addition, genes that are differentially methylated have increasingly been appreciated as a source of clinically relevant biomarker candidates. To identify genes that are specifically methylated during the evolution of resistance to anti-EGFR therapeutic agents, we performed a methylation-specific array containing a panel of 56 genes that are commonly known to be regulated through promoter methylation in two parental non-small cell lung cancer (NSCLC) and head and neck squamous cell carcinoma (HNSCC) cell lines and their resistant derivatives to either erlotinib or cetuximab. We found that death-associated protein kinase (DAPK) was hypermethylated in drug-resistant derivatives generated from both parental cell lines. Restoration of DAPK into the resistant NSCLC cells by stable transfection re-sensitized the cells to both erlotinib and cetuximab. Conversely, siRNA-mediated knockdown of DAPK induced resistance in the parental sensitive cells. These results demonstrate that DAPK plays important roles in both cetuximab and erlotinib resistance, and that gene silencing through promoter methylation is one of the key mechanisms of developed resistance to anti-EGFR therapeutic agents. In conclusion, DAPK could be a novel target to overcome resistance to anti-EGFR agents to improve the therapeutic benefit, and further evaluation of DAPK methylation as a potential biomarker of drug response is needed.

Phospho-ΔNp63α/microRNA network modulates epigenetic regulatory enzymes in squamous cell carcinomas

“…For example, the hypermethylation of the deathassociated protein kinase-1 (DAPK1) promoter was reported to contribute to chemoresistance of cancer cells to several therapeutic agents. 50,51 Intriguingly, the putative TP63 binding sequences in the specific DNMT3A promoter area (−1763 to −1344 bp; Fig. S2) are shown to overlap with the potential DNMT3A consensus sequence.…”

“…[45][46][47] Modulation of DNA methylation affects the DAPK1 expression in SCC cells upon cisplatin exposure Accumulating evidence shows that promoter DNA hypermethylation of various genes involved in cell cycle arrest or apoptosis leads to their epigenetic repression and subsequently to chemoresistance of tumor cells to anticancer drugs. [48][49][50][51] Several DNA methyltransferases, DNMT1, DNMT3A, and DNMT3B, are involved in the addition of methyl groups to the 5′-cytosine at the CpG islands within the specific promoter DNA sequences, subsequently repressing the transcription of these genes. DNMT1 preserves the methylation DNA patterns throughout each cell division, while DNMT3A and 3B transfer a methyl group to unmethylated DNA sequences.…”

Death associated protein kinase-1 gene methylation pattern in some leukemic patients attending Zagazig University hospitals: is it a clue?

“…It was shown to be inactivated by methylation in a variety of humon tumors, including B cell lymphoma, small cell lung cancer, multiple myeloma, gastrointestinal malignancies. [7][8][9] Promoter DAPK1 methylation contribute to the genetic influence on leukemia. On the basis of the central role of the promoter DAPK1 methylation in leukemia, it was hypothesized that DAPK-1 gene methylation pattern is a risk factor for leukemia.…”

“…It was shown to be inactivated by methylation in a variety of humon tumors, including B cell lymphoma, small cell lung cancer, multiple myeloma, gastrointestinal malignancies. [7][8][9] Gonzalez et al showed 14% DAPK1 aberrant methylation in neuroblastic tumours. 10 Sung et al detected 60.9% promoter DAPK 1 methylation in B-cell lymphoma in Korean population.…”

Genome-wide DNA Methylation Analysis Reveals GABBR2 as a Novel Epigenetic Target for EGFR 19 Deletion Lung Adenocarcinoma with Induction Erlotinib Treatment

“…The EGFR 19 deletion cell line PC-9, with the unmethylated promoter region of EGFR gene, was more sensitive to gefitinib compared with the other EGFR 19 deletion cell line H1650 with the methylated promoter region, which was "resistant" to gefitinib, suggesting that EGFR gene promoter methylation may be a potential mechanism for acquired resistance to gefitinib (9). Methylation of death-associated protein kinase (DAPK) is reported to be a novel target with cetuximab and erlotinib resistance (10). DNA methylation regulates gene expression without altering the nucleotide sequence, thereby potentially influencing the sensitivity of EGFR-mutated lung cancer to targeted drugs.…”