[Change in cryolability of tumor stem cells depending on growth phase of Ehrlich adenocarcinoma in vivo].

Cancer stem cells (CSC) are the main structural unit in initia tion, support of in situ growth, as well as tumor metastasis during malignant development of various origin. Observed chemo- and radio-resistance of CSC make them a potential target cell to perform cryoeradication. We have performed a comparative study of changes in functional activity after cryopreservation of CSC of two differentiation levels from Erlich adenocarcinoma (EAC) of various culture terms (EAC-7, EAC-14). It was found that in the case of EAC-7 the expression of cryosuppression in terms of cell functional state at the initial stages of development was bigger in high potency CD44hi cells comparing to more differentiated cells, forming general pool of cells in peritoneal cavity. And vice versa, in the "eldering" EAC-14 this effect was bigger in more differentiated cells comparing to less differentiated ones, even causing in latter (CD44hi) the growth stimulation. Moreover, the minimal proliferative activity of general population cells cEAC- 14 during the first weeks was alternated at the next stage to its maximal expression among all the studied types of EAC cells of both culture terms. These data confirm again the fact, that during assessment of bioobject cryolability (cryostability) it is significant to determine not only cryopreservation conditions, but the initial state of the bioobject as well.