Effect of low doses of actinomycin D on neuroblastoma cell lines

Abstract

BackgroundNeuroblastoma is a malignant embryonal tumor occurring in young children, consisting of undifferentiated neuroectodermal cells derived from the neural crest. Current therapies for high-risk neuroblastoma are insufficient, resulting in high mortality rates and high incidence of relapse. With the intent to find new therapies for neuroblastomas, we investigated the efficacy of low-doses of actinomycin D, which at low concentrations preferentially inhibit RNA polymerase I-dependent rRNA trasncription and therefore, ribosome biogenesis.MethodsNeuroblastoma cell lines with different p53 genetic background were employed to determine the response on cell viability and apoptosis of low-dose of actinomycin D. Subcutaneously-implanted SK-N-JD derived neuroblastoma tumors were used to assess the effect of low-doses of actinomycin D on tumor formation.ResultsLow-dose actinomycin D treatment causes a reduction of cell viability in neuroblastoma cell lines and that this effect is stronger in cells that are wild-type for p53. MYCN overexpression contributes to enhance this effect, confirming the importance of this oncogene in ribosome biogenesis. In the wild-type SK-N-JD cell line, apoptosis was the major mechanism responsible for the reduction in viability and we demonstrate that treatment with the MDM2 inhibitor Nutlin-3, had a similar effect to that of actinomycin D. Apoptosis was also detected in p53−/−deficient LA1-55n cells treated with actinomycin D, however, only a small recovery of cell viability was found when apoptosis was inhibited by a pan-caspase inhibitor, suggesting that the treatment could activate an apoptosis-independent cell death pathway in these cells. We also determined whether actinomycin D could increase the efficacy of the histone deacetylase inhibitor, SAHA, which is in being used in neuroblastoma clinical trials. We show that actinomycin D synergizes with SAHA in neuroblastoma cell lines. Moreover, on subcutaneously-implanted neuroblastoma tumors derived from SK-N-JD cells, actinomycin D led to tumor regression, an effect enhanced in combination with SAHA.ConclusionsThe results presented in this work demonstrate that actinomycin D, at low concentrations, inhibits proliferation and induces cell death in vitro, as well as tumor regression in vivo. From this study, we propose that use of ribosome biogenesis inhibitors should be clinically considered as a potential therapy to treat neuroblastomas.Electronic supplementary materialThe online version of this article (doi:10.1186/s12943-015-0489-8) contains supplementary material, which is available to authorized users.

A Comprehensive NGS Data Analysis of Differentially Regulated miRNAs, piRNAs, lncRNAs and sn/snoRNAs in Triple Negative Breast Cancer

“…3C) piR-23662 (15 fold, p < 0.003), piR-26526 (10 fold, p < 0.00003), piR-26527 (9 fold, p < 0.00009), piR-30293 (9 fold, p < 0.00009) and piR-26528 (8 fold, p < 0.000008) in TNBC compared to normal tissue. Recent studies have also reported the involvement of specific piRNAs in different cancers, for example, piR-4987, piR-20365, piR-20485, piR-20582 and piR-932 in breast cancer 57, 58, piR-823 and piR651 in gastric cancer 59, 60, upregulated piR-32051, piR-39894, piR-43607 and downregulated piR-38756, piR-57125, piR-30924 in kidney cancer 61, piR-Hep1 in liver cancer 62, downregulated piR-017061 in pancreatic cancer 63, downregulated piR-823 in multiple myeloma, downregulated piR-L-163 in lung cancer 64, and piR-59056, piR-32105 and piR-58099 in colon cancer 65. Analyzing stage-wise differential expression of piRNAs, we found 46 piRNAs were shared between stages I & II; three shared piRNAs in stage II & III whereas no common piRNAs in stages I & III.…”

Piwi-interacting RNAs and PIWI genes as novel prognostic markers for breast cancer

“…Mature forms of these RNAs associate with biogenesis pathway proteins such as Argonaute (AGO) class of proteins: miRNAs and siRNAs with AGO proteins and piRNAs with PIWI proteins [2–5] to guide target specific gene regulation [6, 7]. Gene regulation exerts control at transcriptional and post-transcriptional levels and piRNAs, in association with PIWI proteins, are involved in both levels [8, 9]. For a long time, the only roles of PIWI proteins were believed to be in the regulation of transposons and [10] in the maintenance and development of germinal stem cells [11]; however, the functions of piRNAs and PIWI proteins as epigenetic regulators have started to emerge [1, 12].…”

“…It is increasingly being recognized that the sequence based complementarity may not be restricted to 3′ UTR and may expand to 5′UTR, the coding sequence or even the introns [20]. Given the diverse functions of piRNAs and PIWI proteins, it is evident that these molecules may also contribute to tumorigenesis [9]. …”

“…Although the expression of PIWI proteins in somatic tissues has been known since 1998, our major understanding of these molecules stem from germ cells. Only recently, have researchers demonstrated their possible involvement in tumorigenesis [9]. Aberrant expressions of these genes and proteins in malignancy have been associated with hallmarks of cancer and have also shown promise as potential prognostic and diagnostic markers for different cancer types [22].…”

Preparation of single-cell suspension from mouse breast cancer focusing on preservation of original cell state information and cell type composition

“…Although the treatment with ActD as well as the treatment at the lower dissociation temperature led to lower viability, the change was statistically insignificant relative to the control. However, we expected that the administration of ActD would lead to an increase in the number of dying cells (its toxic effect published by Cortes et al (2016)), and subsequently to lower cell 7 yield. Surprisingly, the yield was comparable or even higher during dissociation at 37 °C ( Figure 4B).…”