Adipocytes Isolated from Visceral and Subcutaneous Depots of Donors Differing in BMI Crosstalk with Colon Cancer Cells and Modulate their Invasive Phenotype.

Purpose: Mechanisms related the crosstalk between adipocytes and colon cancer cells are still not clear. We hypothesize that molecules and adipocytokines generated from the adipose tissue of obese individuals accentuate the effect on the metabolic reprogramming in colon cancer cells, i.e. induce disarray in energy metabolism networks of the targeted affected colonic epithelial cells, prompting their malignant phenotype.

Methods: To explore the mechanistic behind this crosstalk we conducted a co-culture model system using human colon cancer cells having different malignant abilities and adipocytes from different depots and subjects.

Results: The results demonstrate that co-culturing aggressive colon cancer cells such as HM-7 cells, with Visceral or Subcutaneous adipocytes (VA or SA respectively) from lean/obese subjects significantly up-regulate the secretion of the adipokines IL-8, MCP1, and IL-6 from the adipocytes. Surprisingly, the response of co-culturing HM-7 cells with obese SA was substantially more significant. In addition, these effects were significantly more pronounced when using HM-7 cells as compared to the less malignant HCT116 colon cancer cells. Moreover, the results showed that HM-7 cells, co-cultured with VA or SA from obese subjects, expressed higher levels of fatty acid binding protein 4; thus, the conditioned media obtained from the wells contained HM-7 cells and adipocytes from obese subjects was significantly more efficient in promoting invasion of HM-7 cells.

Conclusions: We conclude that interaction between adipocytes and colon cancer cells, especially the highly malignant cells, results in metabolic alterations in colon cancer cells and in highly hypertrophy phenotype which characterized by increasing adipokines secretion from the adipocytes.