Different sensitivity to antibiotics of the established intermitent in vivo--in vitro tumor cell lines in comparison with the primary cultures.

From original strains of tumors growing only in vivo (I) new lines of strains (II) were obtained, the cells of which proliferated readily both in vitro and in vivo. Sensitivity in all the new strains (II) generally increased but in varying degrees as against individual cancerostatic drugs, as evident from the given ID50 values and sensitivity indices. In addition to an enhanced sensitivity of the strains to inhibitors, their ability to utilize precursors of the synthesis of nucleic acids and proteins in a linear dependence during the course of 24 hours has also been determined.