Bortezomib induces methylation changes in neuroblastoma cells that appear to play a significant role in resistance development to this compound

Abstract

The anticancer activity of bortezomib (BTZ) has been increasingly studied in a number of indications and promising results for the use of this treatment have been shown in neuroblastoma. As BTZ treatment is usually administered in cycles, the development of resistance and side effects in patients undergoing therapy with BTZ remains a major challenge for the clinical usage of this compound. Common resistance development also means that certain cells are able to survive BTZ treatment and bypass molecular mechanisms that render BTZ anticancer activity. We studied the methylome of neuroblastoma cells that survived BTZ treatment. Our results indicate that BTZ induces pronounced genome wide methylation changes in cells which recovered from the treatment. Functional analyses of identified methylation changes demonstrated they were involved in key cancer pathology pathways. These changes may allow the cells to bypass the primary anticancer activity of BTZ and develop a treatment resistant and proliferative phenotype. To study whether cells surviving BTZ treatment acquire a proliferative phenotype, we repeatedly treated cells which recovered from the first round of BTZ treatment. The repetitive treatment led to induction of the extraordinary proliferative potential of the cells, that increased with subsequent treatments. As we did not observe similar effects in cells that survived treatment with lenalidomide, and non-treated cells cultured under the same experimental conditions, this phenomenon seems to be BTZ specific. Overall, our results indicate that methylation changes may play major role in the development of BTZ resistance.

Bortezomib-Induced Epigenetic Alterations in Nerve Cells: Focus on the Mechanisms Contributing to the Peripheral Neuropathy Development

“…Epigenetic changes that arise because of the action of BTZ cause global changes in the functioning of cells. As we showed in our previous study [ 27 ], treatment of SH-SY5Y tumor cells with a single dose of BTZ caused a complete change in the DNA methylation profile, which is probably responsible for the development of resistance to BTZ. This proves the multidirectional activity of BTZ and its influence on the dysregulation of thousands of genes and miRNA molecules, disrupting many signaling pathways and biological processes.…”

“…BTZ is able to initiate epigenetic changes by altering the level of global DNA methylation in MM patients [ 24 ] and is involved in the regulation of miRNAs’ levels [ 14 , 25 , 26 ]. In our previous studies [ 27 ], we have shown significant epigenetic changes, manifested by a complete change in the DNA methylation profile, induced by the action of BTZ on cancer neuroblastoma cells. We have also observed that DNA methylation changes transferred to daughter cells are possibly involved in the development of resistance to BTZ.…”

Long-Term Treatment with Bortezomib Induces Specific Methylation Changes in Differentiated Neuronal Cells

“…We have recently published a study describing a key role of BTZ-induced methylation changes in the development of resistance to BTZ of the SH-SY5Y neuroblastoma cell line, subjected to treatment with this compound [ 13 ]. To investigate whether methylation changes induced by BTZ in dLUHMES cells are specific to these cells, we analyzed the methylation level of a subset of CpG sites that we identified to be affected by BTZ exposure, using the data from our previous study.…”

“…To assess the specificity of identified methylation changes, we compared the methylation levels at the CpG sites that exhibited methylation changes after BTZ treatment in dLUHMES cells with the methylation levels observed in SH-SY5Y cells, used in our previous analysis of the influence of BTZ treatment on cell methylomes [ 13 ].…”

“…We have previously shown that BTZ induces genome-wide methylation changes in human neuroblastoma SH-SY5Y cells treated with this compound, and these changes are likely to play a significant role in the development of resistance to BTZ [ 13 ]. With clear evidence of the activity of BTZ towards DNA methylation in neuroblastoma cells, we hypothesized in this study that BTZ may also affect the methylomes of mature neurons.…”