Calcium-regulatory proteins as modulators of chemotherapy in human neuroblastoma

Abstract

Neuroblastoma (NB) is a pediatric cancer treated with poly-chemotherapy including platinum complexes (e.g. cisplatin (CDDP), carboplatin), DNA alkylating agents, and topoisomerase I inhibitors (e.g. topotecan (TOPO)). Despite aggressive treatment, NB may become resistant to chemotherapy. We investigated whether CDDP and TOPO treatment of NB cells interacts with the expression and function of proteins involved in regulating calcium signaling. Human neuroblastoma cell lines SH-SY5Y, IMR-32 and NLF were used to investigate the effects of CDDP and TOPO on cell viability, apoptosis, calcium homeostasis, and expression of selected proteins regulating intracellular calcium concentration ([Ca2+]i). In addition, the impact of pharmacological inhibition of [Ca2+]i-regulating proteins on neuroblastoma cell survival was studied. Treatment of neuroblastoma cells with increasing concentrations of CDDP (0.1−10 μM) or TOPO (0.1 nM−1 μM) induced cytotoxicity and increased apoptosis in a concentration- and time-dependent manner. Both drugs increased [Ca2+]i over time. Treatment with CDDP or TOPO also modified mRNA expression of selected genes encoding [Ca2+]i-regulating proteins. Differentially regulated genes included S100A6, ITPR1, ITPR3, RYR1 and RYR3. With FACS and confocal laser scanning microscopy experiments we validated their differential expression at the protein level. Importantly, treatment of neuroblastoma cells with pharmacological modulators of [Ca2+]i-regulating proteins in combination with CDDP or TOPO increased cytotoxicity. Thus, our results confirm an important role of calcium signaling in the response of neuroblastoma cells to chemotherapy and suggest [Ca2+]i modulation as a promising strategy for adjunctive treatment.

Unexpected Growth-Promoting Effect of Oxaliplatin in Excision Repair Cross-Complementation Group 1 Transfected Human Colon Cancer Cells

“…Further, the growth of these transfected tumour cells could be slowed down by a specific protein whose action could be inhibited by interaction with oxaliplatin through, for example, platinum-protein adducts formed on thiol groups in the protein. It could also be that oxaliplatin modulates the intracellular concentrations of calcium as described for cisplatin [27], and that this would influence the behaviour of Trop2 activity, in particular in Trop2 overexpressing cells. Further, the intracellular distribution of ERCC1 protein could be different between the 2 cell models.…”

Targeting Intracellular Calcium Signaling ([Ca2+]i) to Overcome Acquired Multidrug Resistance of Cancer Cells: A Mini-Overview

“…Specific issues that have to be addressed in future research are: Identification and validation of genes that are deregulated upon chemotherapy: ((multi-) drug resistance and calcium modulating genes associated with cancer pathology (e.g., ABCB1, ABCC1, ABCG1, ITPR1, CACNG1, CACNA1D, CAMLG, CALB2, S100A, and TRPV family) (see recent work of [64]).The establishment and characterization of the relationship between deregulation of calcium signaling and MDR expression upon chemotherapy in cancer cells.The identification and validation of selected MDR and calcium signaling related genes associated with acquired drug resistance of cancer cells.The verification on how and why specific manipulations of calcium signaling in drug resistant cancer cells will overcome the drug resistance.To determine of the role of epigenetic manipulation of MDR and calcium signaling related genes will influence the acquired drug resistance of drug resistant cancer cells.…”

Emerging molecular mechanisms in chemotherapy: Ca2+ signaling at the mitochondria-associated endoplasmic reticulum membranes

“…Hence, Bcl-2 seems to form a potential therapeutic target to improve cisplatin therapy of ovarian cancer cells. Additionally, in neuroblastoma cells, cisplatin-induced cell death was preceded by a rise in cytosolic [Ca 2+ ] 144 . Cisplatin treatment also increased the expression levels of several Ca 2+ -transport systems, including IP 3 R3, RyR3, and the S100 Ca 2+ -binding protein A6.…”