An in vitro tumor recurrence model based on platinum-resistant colon cancer cells as a research tool for studying cancer cell dormancy
Fig 2
Cell cycle dynamics and proliferation gene expression in FUCCI-expressing oxaliplatin-resistant HCT116 cells following 150 µM oxaliplatin treatment for 6 hours.
(A) Representative fluorescent microscopy images showing FUCCI signals over time. Red (mKO2-Cdt1) marks G1 phase; green (Clover-Geminin) marks S/G2/M phases. Scale bars: 100 µm. (B) Schematic representation of the experimental timeline and cellular redistribution following oxaliplatin treatment. The diagram illustrates the transition of cells from a proliferating state to a maximally enriched population of resting/dormant cells by day 6 post-oxaliplatin treatment. The sequential fluorescence of FUCCI markers is depicted, showing cells in G1 phase (red fluorescence); сells in S/G2/M phases (green fluorescence); сells transitioning between phases (yellow/orange (red + green overlap)). The dynamic shift in fluorescence reflects cell cycle arrest and enrichment of quiescent/dormant cells following chemotherapy-induced stress. (C) Quantification of cell cycle phase distribution over time. Bars represent the mean percentage of cells in G0/G1, S, or G2/M phases based on FUCCI signal classification. (D) Normalized expression of proliferation-related genes MKI67, AURKA, cyclin A, cyclin B after oxaliplatin exposure (days 0-10), relative to day 0, measured by qPCR, with GAPDH as endogenous control. Bars represent mean relative expression (± SD) from triplicate samples at days 0, 3, 6, and 10 post-treatment.