Modulation of cellular redox state underlies antagonism between oxaliplatin and cetuximab in human colorectal cancer cell lines

Abstract

Background and purpose:Oxaliplatin is the first platinum-based compound effective in the treatment of colorectal cancer. Oxaliplatin combined with cetuximab for metastatic colorectal cancer is under evaluation. The preliminary results seem controversial, particularly for the use of cetuximab in K-Ras mutated patients. K-Ras mutation is known to affect redox homeostasis. Here we evaluated how the efficacy of oxaliplatin alone or combined with cetuximab varied according to the Ras mutation and redox status in a panel of colorectal tumour cell lines. Experimental approach: Viability was evaluated by methylthiazoletetrazolium assay, reactive oxygen species production by DCFDA and lucigenin on HT29-D4, Caco-2, SW480 and SW620 cell lines. Key results: Combination of oxaliplatin and cetuximab was less cytotoxic than oxaliplatin alone in colorectal cells harbouring wild-type Ras and membrane expression of receptors for epidermal growth factor receptor (EGFR), such as HT29-D4 and Caco-2 cells. In contrast, cetuximab did not affect oxaliplatin efficiency in cells harbouring K-Ras V12 mutation, irrespective of membrane EGFR expression (SW620 and SW480 cells). Transfection of HT29-D4 with K-Ras V12 decreased oxaliplatin IC50 and impaired cetuximab sensitivity, without affecting expression of membrane EGFR compared with HT29-D4 control. Oxaliplatin efficacy relies on endogenous production of H2O2. Cetuximab inhibits H2O2 production inhibiting the EGFR/Nox1 NADPH oxidase pathway. Oxaliplatin efficacy was impaired by short hairpin RNA for Nox1 and by catalase (H2O2 scavenger). Conclusions and implications: Cetuximab limited oxaliplatin efficiency by affecting the redox status of cancer cells through Nox1. Such combined therapy might be improved by controlling H2O2 elimination.

Effects of olive oil polyphenols on fatty acid synthase gene expression and activity in human colorectal cancer cells

“…Low grade of differentiation and K-ras mutation [3] could make SW620 cells more sensitive to the induction of apoptosis, whereas HT-29 cells, negative for K-ras mutation, seem to be more resistant. Experimental data [5,6,19] suggest a multifaceted action of polyphenols on the modulation of cell signals and biochemical pathways involved in cell survival and cell death.…”

The Development and Maintenance of Paclitaxel-induced Neuropathic Pain Require Activation of the Sphingosine 1-Phosphate Receptor Subtype 1

“…Anticancer Activity-The effects of FTY720 on the anticancer activity of paclitaxel on human breast adenocarcinoma cells (SKBr3) (41) or of oxaliplatin on human colon carcinoma cells (SW480) (42) were assessed using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay adapted from a previously described assay (43,44). Cells were cultured and assayed in DMEM (SKBr3, Mediatech) or L15 (SW480, Sigma) media supplemented with 10% FBS (Thermo Fisher Scientific) and penicillin/streptomycin (Invitrogen).…”

Targeting the Overproduction of Peroxynitrite for the Prevention and Reversal of Paclitaxel-Induced Neuropathic Pain

“…The effects of MnTE-2-PyP 5ϩ on antitumor activity of paclitaxel on well characterized human breast cancer cells (SKBR3) (Swift et al, 2010;Itamochi et al, 2011) and human ovarian cancer cells (SKOV3) (Lacroix and Leclercq, 2004;Swift et al, 2010;Wu et al, 2010) was assessed using an MTT assay adapted from a previously described assay (Dahan et al, 2009;Kriedt et al, 2010). Cells were cultured and assayed at 37°C, 95% humidity, and 5% CO 2 in DMEM (SKBR3) or McCoy's 5A (SKOV3) medium, each supplemented with 10% FBS and penicillin/streptomycin.…”