Interplay of nutrient stress and lipid dynamics in colorectal cancer cells

Summary: Objectives: A crosstalk between tumor cells and the microenvironment affects the cellular lipid metabolism. Metabolic stress in cancer cells alters the equilibrium between endogenous synthesis and external intake of fatty acids. We aimed to examine the perturbations in intracellular lipids under nutrients stress conditions and to correlate it with the proliferation rates of colorectal cancer cells. Methods: HCT-116 cells were cultured under low-serum conditions (1%, 2%, and 5% serum) compared to control conditions (10% serum) to induce metabolic stress. MTT assay was employed to assess the impact of nutrient deprivation on cell proliferation by measuring absorbance at 540 nm. Lipid accumulation was estimated spectrophotometrically at 510 nm using Oil red O staining method. All the experiments were performed in triplicates and showed consistent reproducibility. Unpaired t-test was applied to compare two groups while multiple groups' comparison was done by ANOVA considering p-value ≤0.05 statistically significant. Results: We found that at low serum conditions the cancer cells showed distorted morphology and lower proliferation rates (p = <0.001). Moreover, Lipid accumulation was found to be very minute in low serum conditions and was directly proportional to proliferation rates (r2 = 0.978). Conclusion: Lipid metabolism varies across different types of cancer. Some cells mainly depend upon the uptake of lipids while others can synthesize their lipids. Therefore, targeting different cancers in the same way is not the solution. Specially, when targeting lipid metabolism to cure cancer we need to study in detail the lipid source of cancer cells.