Retinoic acid–induced survival effects in SH‐SY5Y neuroblastoma cells

Abstract

Neuroblastoma is a malignant childhood cancer arising from the embryonic sympathoadrenal lineage of the neural crest. Retinoic acid (RA) is included in the multimodal therapy of patients with high‐risk neuroblastoma to eliminate minimal residual disease. However, the formation of RA‐resistant cells substantially lowers 5‐year overall survival rates. To examine mechanisms that lead to treatment failure, we chose human SH‐SY5Y cells, which are known to tolerate incubation with RA by activating the survival kinases Akt and extracellular signal‐regulated kinase 1/2. Characterization of downstream pathways showed that both kinases increased the phosphorylation of the ubiquitin ligase mouse double minute homolog 2 (Mdm2) and thereby enhanced p53 degradation. When p53 signaling was sustained by blocking complex formation with Mdm2 or enhancing c‐Jun N‐terminal kinase (JNK) activation, cell viability was significantly reduced. In addition, Akt‐mediated phosphorylation of the cell‐cycle regulator p21 stimulated complex formation with caspase‐3, which also contributed to cell protection. Thus, treatment with RA augmented survival signaling and attenuated basal apoptotic pathways in SH‐SY5Y cells, which increased cell viability.

Alternative Polyadenylation of ABC Transporters of the C-Family (ABCC1, ABCC2, ABCC3) and Implications on Posttranscriptional Micro-RNA Regulation

“…Enrichment of membrane proteins was accomplished using the Plasma Membrane Protein Extraction Kit (Abcam, Berlin, Germany) with 500 ml Homogenize Buffer Mix according to the manufacturer's protocol. Protein quantification and Western blotting were executed according to standard protocols as previously described (Waetzig et al, 2019). Blots were probed with the following antibodies: ABCC2 (c-518048, dilution 1:100; Santa Cruz Biotechnology), GAPDH (sc-47724, dilution 1:5000; Santa Cruz Biotechnology), and anti-mouse (IRDye 800CW 926-32210, dilution 1:10,000; LiCOR, Bad Homburg, Germany).…”

Genome‑wide expression and methylation analyses reveal aberrant cell adhesion signaling in tyrosine kinase inhibitor‑resistant CML cells

“…Whole cell lysates and immunoblotting. Whole cell lysates and immunoblotting were performed as previously described (17,23,24) Cell adhesion assay. Corning Matrigel basement membrane mix (VWR) was thawed overnight at 4˚C.…”

All trans retinoic acid as a host-directed immunotherapy for tuberculosis

“…In addition to the genomic mechanisms, non-genomic mechanisms of RA have been discussed. Studies have reported that RA can activate ERK1/2 kinases ( Bruck et al, 2009 ; Waetzig et al, 2019 ; Cañón et al, 2004 ) which may have a role in cytoskeletal rearrangement and neurite outgrowth ( Pan et al, 2005 ). Also, retinoylation (RA acylation) - a post-translational alteration of proteins by eukaryotic cells ( Das et al, 2014 ) which may have a role in cell differentiation ( Takahashi and Breitman, 1989 ).…”