The human cancer cell lines HeLa, JEG-3, Hep G2, SSC-9, PC-3, HT-29, MCF7 and their isolated nuclei were characterized by differential scanning calorimetry. The calorimetric profiles differed from normal human fibroblast (BJ) cells in the two well distinguished temperature ranges the high-temperature range (HT, due to DNA-containing structures) and the low-temperature range (LT, assigned to the nuclear matrix and cellular proteins). The enthalpy of the LT range, and, respectively the ratio of the enthalpies of the LT vs. HT-range, I.HL/IHH, is strongly reduced for all cancer cells compared to normal fibroblasts. On the contrary, for most of the cancer nuclei this ratio is higher compared to normal nuclei. The HT-29 human colorectal cancer cells/nuclei differed most drastically from normal human fibroblast cells/nuclei. Our data also reveal that the treatment of HT-29 cancer cells with cytostatic drugs affects not only the DNA replication but also the cellular proteome. (C) 2015 Elsevier B.V. All rights reserved.