Exploring Serum Biomarkers for Neuropathic Pain in Rat Models of Chemotherapy-Induced Peripheral Neuropathy: A Comparative Pilot Study with Oxaliplatin, Paclitaxel, Bortezomib, and Vincristine

Abstract

Blood biomarkers, including neurofilament light chain (NfL), have garnered attention as potential indicators for chemotherapy-induced peripheral neuropathy (CIPN), a dose-limiting adverse effect of neurotoxic anticancer drugs. However, no blood biomarker has been established for routine application or translational research. This pilot study aimed to evaluate a limited panel of blood biomarkers in rat models of CIPN and their correlations with neuropathic pain. CIPN models were induced through repeated injections of oxaliplatin, paclitaxel, bortezomib, and vincristine. Electronic von Frey testing was used to assess tactile allodynia. Post anticancer injections, serum concentrations of 31 proteins were measured. Allodynia thresholds decreased in anticancer-treated animals compared to controls. No consistent modifications were observed in the biomarkers across CIPN models. The most noteworthy biomarkers with increased concentrations in at least two CIPN models were NfL (paclitaxel, vincristine), MCP-1, and RANTES (oxaliplatin, vincristine). Vincristine-treated animals exhibited strong correlations between LIX, MCP-1, NfL, and VEGF concentrations and tactile allodynia thresholds. No single biomarker can be recommended as a unique indicator of CIPN-related pain. Because of the study limitations (single dose of each anticancer drug, young animals, and single time measurement of biomarkers), further investigations are necessary to define the kinetics, specificities, and sensitivities of MCP-1, RANTES, and NfL.

Keywords: animal model; blood biomarker; bortezomib; chemotherapy-induced peripheral neuropathy; neuropathic pain; oxaliplatin; paclitaxel; vincristine.

Figure 1

Timeline for the induction of animal models of CIPN, assessment of tactile allodynia, and blood sampling.

Figure 2

Flow diagram of animal inclusion in the analysis.

Figure 3

Weight of animals and tactile allodynia thresholds. (A) Weight of animals treated by anticancer drugs (oxaliplatin, paclitaxel, bortezomib, and vincristine) in comparison to control animals. The results are expressed in grams and presented by mean + standard deviation for control animals (white circle, n = 8–12 animals per anticancer drugs) and anticancer-treated animals (full triangle, n = 8–12 animals per anticancer drugs). Black arrows indicate the day of the anticancer drug injection. (B) Tactile allodynia thresholds (electronic von Frey test) of animals treated by anticancer drugs (oxaliplatin, paclitaxel, bortezomib, and vincristine) in comparison to control animals, before (day 0—basal values) and after the end of anticancer drug injections. The results are expressed in grams and presented by mean + standard deviation for control animals (white bar, n = 8–12 animals per group) and anticancer-treated animals (full bar, n = 8–12 animals per group). * p < 0.05, ** p < 0.01, and *** p < 0.001 control vs. anticancer drug treated animals (repeated-measure ANOVA followed by a post hoc Tukey–Kramer test).

Figure 4

Concentrations of the most significant biomarkers (Fractalkine, IL-10, IL-18, IP-10, LIX, MCP-1, MIP-1α, NfL, RANTES, and VEGF). Results are presented by the mean ± standard deviation for each biomarker and for each animal group. * p < 0.05, ** p < 0.01, and *** p < 0.001 (Kruskal–Wallis test).

Figure 5

Heatmap of the correlations between the serum concentrations of biomarkers and tactile allodynia thresholds after the end of anticancer injections, and for each anticancer drug. Correlation coefficients were calculated between tactile allodynia thresholds on day 28 for oxaliplatin, on day 9 for paclitaxel, on day 9 for bortezomib, and on day 11 for vincristine, and biomarker concentrations, including all the animals (controls and anticancer drug-treated animals). * p < 0.05.

Figure 6

Two-dimensional representation of the factorial analysis of mixed data. The factorial analysis of mixed data included continuous variables (last weight measures, variations in weight between the first and the last measures, last tactile allodynia thresholds, variations in tactile allodynia threshold between the first and the last measures, serum concentrations of fractalkine, IL-1β, IL-2, IL-12(p70), IL-5, IL-17A, IL-18, IP-10, leptin, LIX, MIP-1α, MCP-1, NfL, OPN, RANTES, VEGF, and TNFα) and categorical variables (serum concentrations of eotaxin (≤4.65, >4.65), G-CSF (≤4.48, >4.48), IFNγ (≤10.45, >10.45), IL-1α (≤39.845, >39.845), IL-4 (≤17.93, >17.93), IL-6 (≤279.85, >279.85), IL-13 (≤17.525, >17.525), and IL-10 (≤8.27, >8.27)). The treatment group (oxaliplatin-treated, oxaliplatin vehicle-treated (control of oxaliplatin), paclitaxel-treated, paclitaxel vehicle-treated (control of paclitaxel), bortezomib-treated, bortezomib vehicle-treated (control of bortezomib), vincristine-treated, and vincristine vehicle-treated (control of vincristine)) was added as a supplementary variable. The following variables were not included in the model: serum concentrations of EGF, GFAP, GM-CSF, GRO/KC, MIP-2, and NGF.