BACKGROUND: MYCN oncogene amplification occurs in 20-25% of neuroblastoma and is associated with a poor prognosis. We previously reported that MYCN amplified (MNA) p53 wild-type neuroblastoma cell lines failed to G1 arrest in response to irradiation, but this could not be attributed to MYCN alone. HYPOTHESIS: Genes co-amplified with MYCN and/or the predominant cell type, neuronal (N) or substrate adherent (S) phenotypes determine the downstream response to DNA damage in neuroblastoma cell lines. METHODS: The MYCN amplicons of five MNA and two non-MNA cell line were mapped using 50K Single Nucleotide Polymorphism (SNP) arrays. One MNA (NBL-W) and one non-MNA neuroblastoma cell line (SKNSH) were sub-cloned into N and S-type cells and the p53 pathway investigated after irradiation induced DNA damage. To determine the role of p53 it was knocked down using siRNA. RESULTS: No genes with a potential role in cell cycle regulation were consistently co-amplified in the MNA cell lines studied. High MYCN expressing NBLW-N cells failed to G1 arrest following irradiation and showed impaired induction of p21 and MDM2, whereas low MYCN expressing NBLW-S cells underwent a G1 arrest with induction of p21 and MDM2. Conversely N type cells underwent higher levels of apoptosis than S type cells. Following p53 knockdown in SHSY5Y N-type cells there was a decrease in apoptosis. CONCLUSIONS: The downstream response to DNA damage in p53 wild-type neuroblastoma cell lines is p53 dependent, and determined both by the morphological sub-type and MYCN expression.
BACKGROUND:MYCN oncogene amplification occurs in 20-25% of neuroblastoma and is associated with a poor prognosis. We previously reported that MYCN amplified (MNA) p53 wild-type neuroblastoma cell lines failed to G1 arrest in response to irradiation, but this could not be attributed to MYCN alone. HYPOTHESIS: Genes co-amplified with MYCN and/or the predominant cell type, neuronal (N) or substrate adherent (S) phenotypes determine the downstream response to DNA damage in neuroblastoma cell lines. METHODS: The MYCN amplicons of five MNA and two non-MNA cell line were mapped using 50K Single Nucleotide Polymorphism (SNP) arrays. One MNA (NBL-W) and one non-MNA neuroblastoma cell line (SKNSH) were sub-cloned into N and S-type cells and the p53 pathway investigated after irradiation induced DNA damage. To determine the role of p53 it was knocked down using siRNA. RESULTS: No genes with a potential role in cell cycle regulation were consistently co-amplified in the MNA cell lines studied. High MYCN expressing NBLW-N cells failed to G1 arrest following irradiation and showed impaired induction of p21 and MDM2, whereas low MYCN expressing NBLW-S cells underwent a G1 arrest with induction of p21 and MDM2. Conversely N type cells underwent higher levels of apoptosis than S type cells. Following p53 knockdown in SHSY5Y N-type cells there was a decrease in apoptosis. CONCLUSIONS: The downstream response to DNA damage in p53 wild-type neuroblastoma cell lines is p53 dependent, and determined both by the morphological sub-type and MYCN expression.
Authors: Johannes Brägelmann; Stefanie Böhm; Matthew R Guthrie; Gurkan Mollaoglu; Trudy G Oliver; Martin L Sos Journal: Cell Cycle Date: 2017-07-24 Impact factor: 4.534
Authors: Sina Gogolin; Volker Ehemann; Gabriele Becker; Lena M Brueckner; Daniel Dreidax; Steffen Bannert; Ingo Nolte; Larissa Savelyeva; Emma Bell; Frank Westermann Journal: Cell Cycle Date: 2013-03-05 Impact factor: 4.534
Authors: Lindi Chen; Raphaël F Rousseau; Steven A Middleton; Gwen L Nichols; David R Newell; John Lunec; Deborah A Tweddle Journal: Oncotarget Date: 2015-04-30
Authors: Saurabh Agarwal; Giorgio Milazzo; Kimal Rajapakshe; Ronald Bernardi; Zaowen Chen; Eveline Barbieri; Jan Koster; Giovanni Perini; Cristian Coarfa; Jason M Shohet Journal: Oncotarget Date: 2018-04-17