A cyclopalladated complex interacts with mitochondrial membrane thiol-groups and induces the apoptotic intrinsic pathway in murine and cisplatin-resistant human tumor cells

Background Systemic therapy for cancer metastatic lesions is difficult and generally renders a poor clinical response. Structural analogs of cisplatin, the most widely used synthetic metal complexes, show toxic side-effects and tumor cell resistance. Recently, palladium complexes with increased stability are being investigated to circumvent these limitations, and a biphosphinic cyclopalladated complex {$ Pd_{2} $ [S(-) $ C^{2} $, N-dmpa]2 (μ-dppe)$ Cl_{2} $} named C7a efficiently controls the subcutaneous development of B16F10-Nex2 murine melanoma in syngeneic mice. Presently, we investigated the melanoma cell killing mechanism induced by C7a, and extended preclinical studies. Methods B16F10-Nex2 cells were treated in vitro with C7a in the presence/absence of DTT, and several parameters related to apoptosis induction were evaluated. Preclinical studies were performed, and mice were endovenously inoculated with B16F10-Nex2 cells, intraperitoneally treated with C7a, and lung metastatic nodules were counted. The cytotoxic effects and the respiratory metabolism were also determined in human tumor cell lines treated in vitro with C7a. Results Cyclopalladated complex interacts with thiol groups on the mitochondrial membrane proteins, causes dissipation of the mitochondrial membrane potential, and induces Bax translocation from the cytosol to mitochondria, colocalizing with a mitochondrial tracker. C7a also induced an increase in cytosolic calcium concentration, mainly from intracellular compartments, and a significant decrease in the ATP levels. Activation of effector caspases, chromatin condensation and DNA degradation, suggested that C7a activates the apoptotic intrinsic pathway in murine melanoma cells. In the preclinical studies, the C7a complex protected against murine metastatic melanoma and induced death in several human tumor cell lineages in vitro, including cisplatin-resistant ones. The mitochondria-dependent cell death was also induced by C7a in human tumor cells. Conclusions The cyclopalladated C7a complex is an effective chemotherapeutic anticancer compound against primary and metastatic murine and human tumors, including cisplatin-resistant cells, inducing apoptotic cell death via the intrinsic pathway..

Medienart:

E-Artikel

Erscheinungsjahr:

2011

Erschienen:

2011

Enthalten in:

Zur Gesamtaufnahme - volume:11

Enthalten in:

BMC cancer - 11(2011), 1 vom: 14. Juli

Sprache:

Englisch

Beteiligte Personen:

Serrano, Fabiana A [VerfasserIn]
Matsuo, Alisson L [VerfasserIn]
Monteforte, Priscila T [VerfasserIn]
Bechara, Alexandre [VerfasserIn]
Smaili, Soraya S [VerfasserIn]
Santana, Débora P [VerfasserIn]
Rodrigues, Tiago [VerfasserIn]
Pereira, Felipe V [VerfasserIn]
Silva, Luis S [VerfasserIn]
Machado, Joel [VerfasserIn]
Santos, Edson L [VerfasserIn]
Pesquero, João B [VerfasserIn]
Martins, Rafael M [VerfasserIn]
Travassos, Luiz R [VerfasserIn]
Caires, Antonio CF [VerfasserIn]
Rodrigues, Elaine G [VerfasserIn]

Links:

Volltext [kostenfrei]

Themen:

Dppe
Extracellular Acidification Rate
Human Tumor Cell Line
Mitochondrial Membrane Protein
Murine Melanoma Cell

Anmerkungen:

© Serrano et al; licensee BioMed Central Ltd. 2011. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (

doi:

10.1186/1471-2407-11-296

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

SPR027633713