Extracellular matrix thermostability of breast gland carcinoma

Thermostability of epithelial cell matrix in composition of normal and breast ductal carcinoma tissues at various stages of the disease has been studied in the temperature range 40-90°C with help of differential scanning calorimeter (DSC). It has been shown that the denaturation process has three stages of transition in both cases. The temperatures corresponding to maxima of these structural transitions (Td) in case of normal and ductal carcinoma tissues equals to 55 , 66,78 C and 48, 55, 60, 85°C, respectively. Denaturation enthalpy (∆Hd) reflects contribution of hydrogen bonds, electrostatic and hydrophobic interactions in stability of native structures of biomacromolecules; in case of normal tissues, it equals 68,5±6.0 J/g dry biomass and decreases up to 52.5±6.0 J/g dry biomass in stage III of the disease. On the basis of presented and published experimental data, it is affirmed that the dominant transitions with Td around 66 and 60°C in case of norm and carcinoma, accordingly, correspond to denaturation of collagen IV fibers--the main component of microenvironment of duct epithelial cells (ECM)--and weakly expressed transition stages at 55, 78, 85°C correspond to denaturation of cytoplasmatic proteins. It is supposed that the observed significant differences in thermostability, in particular, 6° decrease of the ECM main component collagen, 7° increase of cytoplasmic proteins, and a significant decrease of total ∆Hd in case of ductal carcinoma compared to norm may be used as a new express test together with other existed tests for diagnosis of breast cancer at early stage of disease using some mg quantities of biopsy tissue.