Cell-cell contact affects cellular sensitivity to hyperthermia.

The influence on heat sensitivity of interactions between HT29 human colon adenocarcinoma cells grown in two- or three-dimensional contact was investigated. No evidence for intercellular cooperation affecting cellular sensitivity to hyperthermia was found. Cells grown in monolayer were found to be more heat sensitive than those in aggregates, probably due to the different physical properties of the membrane of flat cells attached to the substratum. Cell-cell contact appears to affect the heat sensitivity of HT29 cells possibly by means of inducing arrest in a heat resistant phase of the cell cycle.