Identification of MRP2 as a targetable factor limiting oxaliplatin accumulation and response in gastrointestinal cancer.

Oxaliplatin is important for the clinical treatment of colorectal cancer and other gastrointestinal malignancies, but tumour resistance is limiting. Several oxaliplatin transporters were previously identified but their relative contributions to determining oxaliplatin tumour responses and gastrointestinal tumour cell sensitivity to oxaliplatin remains unclear. We studied clinical associations between tumour expression of oxaliplatin transporter candidate genes and patient response to oxaliplatin, then experimentally verified associations found with MRP2 in models of human gastrointestinal cancer.

Emerging roles of metal solute carriers in cancer mechanisms and treatment.

The literature concerning the roles of metal transporting solute carriers in the development and progression of human cancer, and in the delivery of metal-containing anticancer drugs, chemical carcinogens and imaging agents, is reviewed. A range of different solute carrier families, including members from the SLC2A, SLC11A, SLC22A, SLC25A, SLC30A, SLC31A, SLC39A, SLC40A, SLC47A and SLCO1B families, and various metal substrates, including arsenic, copper, gadolinium, iron, platinum and zinc, have been implicated in these cancer-related transport processes. For example, the transport of platinum-based anticancer drugs has been reported to be influenced by the expression and activities of OCT1-3 (SLC22A1-3), OCTN1/2 (SLC22A4/5), CTR1/2 (SLC31A1/2) and MATE1/2 (SLC47A1/2) solute carriers.

Contributions of rat Ctr1 to the uptake and toxicity of copper and platinum anticancer drugs in dorsal root ganglion neurons.

Dorsal root ganglion (DRG) neurons are affected by platinum-induced neurotoxicity and neurodegenerative processes associated with disturbed copper homeostasis and transport. This study aimed to understand the role of copper transporter 1 (Ctr1) in the uptake and toxicity of copper and platinum drugs in cultured rat DRG neurons, and the functional activities of rat Ctr1 (rCtr1) as a membrane transporter of copper and platinum drugs. Heterologous expression of rCtr1 in HEK293 cells (HEK/rCtr1 cells) increased the uptake and cytotoxicity of copper, oxaliplatin, cisplatin and carboplatin, in comparison to isogenic vector-transfected control cells.

Oxaliplatin transport mediated by organic cation/carnitine transporters OCTN1 and OCTN2 in overexpressing human embryonic kidney 293 cells and rat dorsal root ganglion neurons.

The organic cation/carnitine transporters OCTN1 and OCTN2 are related to other organic cation transporters (OCT1, OCT2, and OCT3) known for transporting oxaliplatin, an anticancer drug with dose-limiting neurotoxicity. In this study, we sought to determine whether OCTN1 and OCTN2 also transported oxaliplatin and to characterize their functional expression and contributions to its neuronal accumulation and neurotoxicity in dorsal root ganglion (DRG) neurons relative to those of OCTs. [(14)C]Oxaliplatin uptake, platinum accumulation, and cytotoxicity were determined in OCTN-overexpressing human embryonic kidney (HEK) 293 cells and primary cultures of rat DRG neurons.

Oxaliplatin-induced loss of phosphorylated heavy neurofilament subunit neuronal immunoreactivity in rat DRG tissue.

Background: Oxaliplatin and related chemotherapeutic drugs cause painful chronic peripheral neuropathies in cancer patients. We investigated changes in neuronal size profiles and neurofilament immunoreactivity in L5 dorsal root ganglion (DRG) tissue of adult female Wistar rats after multiple-dose treatment with oxaliplatin, cisplatin, carboplatin or paclitaxel.

Results: After treatment with oxaliplatin, phosphorylated neurofilament heavy subunit (pNF-H) immunoreactivity was reduced in neuronal cell bodies, but unchanged in nerve fibres, of the L5 DRG.

Neuronal expression of copper transporter 1 in rat dorsal root ganglia: association with platinum neurotoxicity.

Purpose: We report the neuronal expression of copper transporter 1 (CTR1) in rat dorsal root ganglia (DRG) and its association with the neurotoxicity of platinum-based drugs.

Methods: CTR1 expression was studied by immunohistochemistry and RT-PCR. The toxicity of platinum drugs to CTR1-positive and CTR1-negative neurons was compared in DRG from animals treated with maximum tolerated doses of oxaliplatin (1.