DOHERTY, B, et al., Collateral Sensitivity to Cisplatin in Kb-8-5-11 Drug-Resistant Cancer Cells. Anticancer Research, 2014. 34(503-508.
KB-8-5-11 cells are a drug-resistant cervical cell model that overexpresses ABCB1 (P-glycoprotein). KB-8-5-11 has become sensitive to non-ABCB1 substrate cisplatin. Understanding the mechanism of collateral sensitivity to cisplatin may lead to biomarker discovery for platinum sensitivity in patients with cancer.
MATERIALS AND METHODS:
A Taqman low-density array was used to characterize the expression of 380 genes previously associated with chemoresistance. Identified pathways were further analyzed using cytotoxicity assays, metabolomics and western blots.
KB-8-5-11 cells were sensitive to CuSO4 and the glutathione inhibitor buthionine sulphoximine. Expression of ATPase, Cu(2+) transporting alpha (ATP7A) and ATP7B were decreased at the protein and gene levels respectively in KB-8-5-11. KB-8-5-11 had decreased gene expression of glutathione S-transferase pi 1 (GSTP1), GSTA4 and GSTK1. Cisplatin treatment significantly lowered total cellular glutathione in parental KB-3-1 cells. Glutathione also tended to be lower in KB-8-5-11 cells compared to KB-3-1 cells.
KB-8-5-11 cells have alterations in their copper transporters and glutathione metabolism, contributing to their cisplatin-sensitive phenotype.
Cisplatin, KB-8-5-11 cells, cervical cancer, collateral sensitivity, drug resistance, paclitaxel