Total proteolytic activity and content of the main proteinase inhibitors in blood plasma of rats bearing doxorubicin-sensitive and doxorubicin-resistant Guerin carcinoma.

UNLABELLED: The AIM of work was to evaluate the alteration of the total proteolytic activity (TPA) and the levels of alpha(1)-proteinase inhibitor (alpha1PI) and alpha(2)-macroglobuline (alpha2M) in blood plasma of rats bearing Guerin carcinoma upon the development of Doxorubicin (DOX) resistance. MATERIALS AND METHODS: TPA and alpha1PI and alpha2M content in the blood plasma of male Wistar rats bearing DOX-resistant and DOX-sensitive Guerin carcinoma were evaluated by standard biochemical methods. RESULTS: During growth of both DOX-sensitive and DOX-resistant Guerin carcinoma, TPA decrease in blood plasma and the increase of alpha1PI levels were registered; in DOX-resistant group this effect was more pronounced. Alpha2M content in blood plasma of animals from both experimental groups was considerably smaller than that of the control and was the lowest in DOX-resistant group. CONCLUSION: The growth of DOX-resistant Guerin carcinoma is accompanied by imbalance of proteolysis processes in the blood plasma, particularly, alteration of TPA and alpha1PI and alpha2M levels.

Structural organisation of nucleic acids from tumour cells.

The DNA from Carcinoma Guerina resistant and sensitive cells of Wistar line rats and their interaction with anti-cancer drugs--cis-platin and doxorubicin (DOX)--have been studied in in vivo experiments. Surface enhanced infrared absorption (SEIRA) in reflectance absorption spectroscopy (RAS) mode was applied for registration of conformational change of the DNA induced by cancer process and anti-cancer drugs. We have registered numerous minor changes in infrared spectra of the DNA from sensitive and resistant cells that could reflect essential changes in molecular structure of DNA from cancer cells. The most significant transformation was undergone by the sugar phosphate backbone of the DNA from cancer cells. The DNA from resistant cancer cells could be characterized as rigid structures and look like the canonical helix form of DNA being practically unchangeable after anti-cancer drug application. The structure of DNA from sensitive cancer cells seems to be flexible and after application of anti-cancer drugs drastically changes and approaches to structure of helix form. It has been shown that doxorubicin strongly influences the DNA structure, leading to DNA stabilization and formation of new H-bonds in DNA doxorubicin complex. We have registered slight cis-platin influence on the DNA structure in in vivo experiment. Principal component analysis of SEIRA spectra can select the DNA from cancer cells.